COAGULATION ASSAY APPARATUS AND METHODS THEREOF
20220373566 · 2022-11-24
Inventors
- Mary Pomeroy (Boynton Beach, FL, US)
- Martina Medkova (Winchester, MA, US)
- Jeff Chien (Wellesley, MA, US)
Cpc classification
G01N33/86
PHYSICS
International classification
Abstract
This invention relates to a method and apparatus for determining the activity of coagulation factors in dilute capillary whole blood, citrated whole blood and citrated plasma. It also includes the detection of the hemoglobin amount in a whole blood sample so a correction of the clotting time can be performed thereby making the clotting time values independent of hemoglobin and hematocrit effect.
Claims
1. A disposable bioassay diagnostic cartridge for monitoring anticoagulant activity, the disposable cartridge comprising: a first well holding an amount of matrix, the matrix being either a drying matrix or a liquid matrix; a second well holding a plurality of microparticles, wherein the plurality of microparticles are uncoated latex with at least one surface type, and the at least one surface type being chosen from a group consisting of unreacted plain, sulfate, carboxylate, and amidine; and a third well comprising an amount of an activation agent, the activation agent being chosen from a group consisting of thromboplastin, thrombin, ellagic acid, activated partial thromboplastin, Factor II, Factor VII, Factor I, Factor X, Factor XII, activated protein C, snake venom, negatively charged phospholipids, calcium ions, tissue factor, silica, koalin, and celite.
2. The disposable cartridge according to claim 1, wherein the matrix further comprises at least one of NaCl, PEG, TWEEN, carbohydrate, and CaCl2.
3. The disposable cartridge according to claim 1, the disposable cartridge further comprising an integrated cuvette capable of facilitating at least two optical detection readings.
4. The disposable cartridge according to claim 1, the disposable cartridge further comprising an integrated cuvette having a first wall capable of facilitating a first optical detection reading via a first LED at 530 nm; and a second wall capable of facilitating a second optical detection reading via a second LED at 660 nm.
5. The disposable cartridge according to claim 1, the disposable cartridge further comprising an integrated cuvette having first and second walls capable of facilitating a first optical detection reading via a first LED at 530 nm, and a second optical detection reading via a second LED at 660 nm.
6. (canceled)
7. A coagulation bioassay comprising: a matrix, the matrix comprising at least one of glycine, sodium chloride, and 1% simethicone; a plurality of microparticles suspended within the matrix, and wherein the plurality of microparticles are uncoated latex having at least one surface type; and an amount of activation agent, the activation agent being chosen from a group consisting of thromboplastin, thrombin, ellagic acid, activated partial thromboplastin, Factor II, Factor VII, Factor I, Factor X, Factor XII, activated protein C, snake venom, negatively charged phospholipids, calcium ions, tissue factor, silica, koalin, and celite.
8. The coagulation bioassay according to claim 7, wherein the at least one surface type is selected from a group consisting of plain, sulfate, amidine, and carboxylate.
9. The coagulation bioassay according to claim 7, wherein the matrix is one of a drying matrix and a liquid matrix.
10. The coagulation bioassay according to claim 7, wherein each of the plurality of microparticles have a diameter of from about 10 nm to 150 nm.
11. The coagulation bioassay according to claim 7, wherein each of the plurality microparticles have a diameter in a range of from 90 nm to 110 nm.
12. The coagulation bioassay according to claim 7, wherein the plurality of microparticles are in a percent weight per volume solution selected from a group consisting of 0.006% weight per volume solution; 0.01% weight per volume solution; and 0.08% weight per volume solution.
13. A method of obtaining clotting time measurements using one of dilute, lysed whole blood, or plasma, the method comprising the steps of: selecting a microparticle matrix having a matrix and a plurality of microparticles within the matrix, wherein the plurality of microparticles are uncoated latex with at least one surface type, and the at least one surface type chosen from a group consisting of unreacted plain, sulfate; carboxylate, and amidine chemical structures retaining activity; using the microparticle matrix as a reagent with the one of dilute, lysed whole blood, or plasma; and obtaining clotting time measurements of the one of dilute, lysed whole blood, or plasma; and determining a hemoglobin level of the one of dilute, lysed whole blood, or plasma; and correcting the clotting time measurements by adjusting for the hemoglobin level of the one of dilute, lysed whole blood, or plasma.
14. The method according to claim 13 further comprising: adding a separate activation agent to the reaction mixture to further activate natural clotting substrates in the one of dilute, lysed whole blood, or plasma.
15. The method according to claim 14 wherein the activation agent is selected from a group consisting of thromboplastin, thrombin, ellagic acid, activated partial thromboplastin, Factor II, Factor VII, Factor I, Factor X, Factor XII, activated protein C, snake venom, negatively charged phospholipids, calcium ions, tissue factor, silica, koalin, and celite.
16. The method according to claim 13 wherein obtaining the clotting time measurements of the one of dilute; lysed whole blood, or plasma further comprises repeatedly measuring an optical density of the one of dilute, lysed whole blood, or plasma, at a first wavelength over a period of time.
17. The method according to claim 16 wherein determining the hemoglobin level of the one of dilute, lysed whole blood, or plasma, comprises measuring an optical density of the one of dilute, lysed whole blood, or plasma, at a second wavelength.
18. The method according to claim 17 wherein the first wavelength is in a range of between 620 nm to 700 nm, and the second wavelength is in a range of between 500 nm to 550 nm.
19. The method according to claim 13 wherein the step of obtaining clotting time measurements of the one of dilute, lysed whole blood, or plasma further comprising obtaining an optical density value difference of at least 0.08.
20. The method according to claim 13 wherein the matrix is a liquid matrix and further comprises 0.17M glycine at pH 10.0, 1.29M NaCl, and 1% simethicone diluted with injection grade purified water.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0026]
[0027]
[0028]
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
[0035]
[0036]
[0037]
[0038]
[0039]
[0040]
[0041]
[0042] Prothrombin with BSA v. Normal
[0043]
[0044]
[0045] Prothrombin with Amidine v. Sulfate v. Plain
[0046]
[0047]
[0048]
[0049]
[0050]
[0051]
[0052] Prothrombin with Simethicone
[0053]
[0054]
[0055]
[0056]
[0057]
[0058] Prothrombin with Carboxyl
[0059]
[0060]
[0061] Prothrombin with Varying Temperatures
[0062]
[0063]
[0064] Prothrombin with Coumadin
[0065]
[0066] Thrombin
[0067]
[0068] Activated Partial Thrombin
[0069]
[0070]
[0071]
[0072]
DETAILED DESCRIPTION OF THE INVENTION
[0073] The preferred embodiments of the present invention are discussed in reference to
General Overviews
[0074] General overviews of the manual and automated portions of the overall method 100, system cartridge 2, and bioassay from various perspectives will now be discussed with indicated reference to
[0075] General Overview of Method from User's Perspective
[0076] A general overview of a user's perspective is now discussed with reference to
[0077] If the bioassay is identified initially, the capillary sampler may be removed from the cartridge 106, filled with the blood sample 107, and replaced in the specified cartridge 108, all within five seconds of performing the fingerstick 105. After replacing the filled sampler 108 back in the cartridge, the identifier may be scanned 103 by the analyzer, and the cartridge inserted into the analyzer 109. After loading the cartridge into the analyzer, the automated process 110 begins. Depending upon the selected bioassay, the automated process will then, according to the specified order of the bioassay components, involve automated steps of adding 112, mixing 114, measuring 116, incubating 117, correcting 118, and reporting 119 the results to the user or other designated individual.
[0078] Depending on the system involved, and the purpose for the bioassay, the automated process 110 may include a further step of automatically adjusting 120 the amount of medication prescribed and/or the amount of medication provided by a built-in medication delivery system (not shown).
[0079] Shown in
[0080] Turning next to
[0081] General Overview of the Bioassay Cartridge
[0082] An exemplary cartridge kit which may be used with the present inventive system and methodology may include a self-contained single-use disposable integrated bioassay cartridge 2 such as now will be described with further reference to
[0083] A first cartridge 2 embodiment, illustrated in
[0084] Both
[0085] Both
[0086] From a user's perspective, the only difference between using the first and second type of cartridges begins now. With the first cartridge, a user may then manually select an automated process option 110 by selecting one of several bioassay options through manual user input via an access control panel on the analyzer. Whereas, with the second cartridge type, insertion of the cartridge 109 alone is sufficient for triggering the automated process 110. For this second cartridge type, from a user's perspective, the bioassay cartridge alone is ‘selected’. However, before a user can select a bioassay option, the bioassay cartridge must first be prepared, and before preparation, the bioassay components themselves must first be selected. Several bioassay cartridge component options will be discussed further below with reference to the initial
[0087] Now looking more specifically at those elements of the cartridge 2 which are not necessarily observed by the user once the sampler 8 has been filled 107 and returned to the cartridge 2. As may be seen in
[0088] During the insertion and setting process, the capillary tube of the sampler 8 is inserted through the lower portion aperture located in an apex end of the capillary wiper. Because the cross-sectional area of the lower portion aperture is smaller than the cross-sectional area of the capillary tube, the lower portion aperture acts like a squeegee against the outside surface of the capillary tube and prevents any sample inadvertently disposed on the outside surface of the capillary tube from entering and being deposited into the chamber 6 of the cartridge 2.
[0089] Also facilitating accuracy, the capillary wiper of these cartridges 2 removes any sample 60 from the outside surface of the capillary tube. Erroneous results are thereby prevented from an “over-filling” of the appropriate well 6′ in the test cartridge 2 with sample 60. Likewise, since the capillary tube is not wiped by the user, there is no, or very little, chance that any sample 60 within the capillary tube is removed inadvertently, which could lead to erroneous results from an “under-filling” of the well 6′ in the test 2 cartridge with sample 60.
[0090] General Overview of Automated Processes
[0091] The cartridge 2 is then inserted into the point-of-care analyzer 1 for the automated testing portions 110 of the blood sample 60 which will now be discussed with further reference to
[0092] The analyzer then uses a small a small sharp point on the cartridge cover to pierce seals for each of the wells 6, 6′, 6″, etc. Seals of the present cartridge 2 may be foil seals, or other covers, so long as they are capable of preventing cross contamination of the contents of the wells during shipping. These seals should also be capable of reducing unregulated water vapor dilution and evaporation.
[0093] The automated arm then retrieves a pipette tip 5 from the first well 6. The pipette tip 5 is then used by the analyzer 1 to move the samples and other bioassay components to the appropriate well for mixing according to the bioassay methods described herein.
[0094] If a dry microparticle matrix 11 is employed, then the pipette 5 aspirates additional diluent 90 from a fourth well 6′″ and adds it according to the protocol to microparticles 11 within the third well 6″, where mixing and stirring occurs forming diluted particles 11. Then, regardless of which type of matrix is employed, the pipette tip 5 aspirates the selected amount of (now diluted) microparticles 11 from the third well 6″ into a second well 6′.
[0095] The cover of the cartridge 2 is then replaced on the cartridge and the pipettor engages the capillary sampler 8 and the sample 60 is thereby added 112 to the second well 6′ where the diluted selected microparticles 11 await. The arm of the analyzer 1 then removes the cover of the cartridge 2 again and the sample 60 and diluted selected particles 11 are then mixed 114 by pipetting up and down, for a first predetermined time forming a mixture 121 of microparticles 11 and sample 60.
[0096] The pipette tip 5 then aspirates the designated amount of the selected, formed matrix 40 from the fifth well 6″″ then, in a second adding step 112, adds the matrix 40 to the second well 6′ which already comprises the mixture 121 of sample 60 and diluted microparticles 11. The matrix 40, and the mixture 121 are then mixed 114, for example, by pipetting up and down, within the second well 6′ for a second predetermined time forming a solution 122 (having matrix 40, sample 60, and microparticles 11).
[0097] Afterwards, the pipette 5 aspirates a predetermined amount of the solution 122 (comprising the matrix 40, sample 60, and microparticles 11) from the second well 6′ and adds 112 this solution 122 to a seventh well 7 in the cartridge 2 comprising the selected reagent 80. The solution 122 (microparticles, the matrix, the sample) and the reagent 80 are then mixed for a third predetermined time forming a commixture 123 (now having matrix 40, sample 60, microparticles 11, and reagent 80).
[0098] If performed with a preferred cartridge 2 as shown in
[0099] Initiating the first measurement 112, a first light emitting device (LED) of the analyzer 1 is turned on, the light from the first LED is transmitted a wavelength of 660 nm through a first wall of the integrated cuvette 7. The light is then transmitted through the commixture 123, and through a second wall of the integrated cuvette until the light is then detected by a light detector of the analyzer. Continuous readings are collected over a predetermined amount of time to provide first clotting data 124.
[0100] For the second measurement 112′, a second light emitting device (LED) of the analyzer 1 is turned on, the light from the second LED is transmitted at a second wavelength of 530 nm through the first wall of the integrated cuvette 7. The light is then transmitted through the commixture 123, and back through the second wall of the integrated cuvette 7 until the light is then collected by a light detector of the analyzer. Only a single reading is necessary to provide the Hemoglobin level data 125. It is to be recognized that although these measurements are called first and second, the order may be reversed. Alternatively, instead of providing the measurements sequentially, they may be provided contemporaneously, or even partially concurrently.
[0101] As will be discussed further below, the results from the optical detection 116, 116′ are then used to correct 118 the clotting time results 126. It is these corrected results 126 which are then reported to the user.
[0102] General Overview of Bioassay Components
[0103] The present invention provides a bioassay cartridge 2 having at least one of several microparticle matrixes 10 which will now be discussed. In some embodiments, the microparticle matrix 10 is formed prior to cartridge formation, in other embodiments, the microparticle matrix 10 is formed after addition 112 of the blood sample 60 during the bioassay process 110.
[0104] The microparticle matrix 10 has microparticles 11 which may be uncoated, unconjugated, protein free, latex, plain, or with surface functionalized groups on polystyrene microparticles. The matrix 40 generally consists of a carbohydrate 46 which facilitates adsorption of biomarker proteins while concomitantly allowing rapid dissolution and uniform dispersion of the microparticles 11. The dispersed nature of the microparticles 11 within the matrix 40 allows adsorption of quantifiable analytical protein biomarkers which are then available for ligand attachment.
[0105] Microparticles 11 used in the present invention include polystyrene microparticles 18 with surface active groups such as amidine 22 and sulfate 24. The microparticles 11 of the present invention range in diameter size 26 from 20 nm to 800 nm or more. The preferred range of particle diameter 26 is 40 nm to 150 nm, with the most preferred diameter 26 being in a range of 75 to 125 nm.
[0106] Amidine Microparticles
[0107] One embodiment of the present invention employs amidine particles 22 having a diameter 26 of 95 nm in a dilution 11 of 0.080% weight per volume 28. The optical density 31 of the dilution 11 was measured at 660 nm, for an optical density value of 0.19.
[0108] The amidine microparticles 22 of the present invention range in diameter size 26 from 20 nm to 800 nm or more. The preferred range of particle diameter 26 is 40 nm to 150 nm, a more preferred diameter 26 being in a range of 75 to 125 nm; and the most preferred diameter being in a range of 90 nm to 98 nm. The amidine microparticles 22 are in a dilution 11 in a range of 0.006%-8% weight by volume 28, and more preferably in a dilution 11 having a range of 0.010%-0.20% weight by volume, and most preferably a dilution 11 having a 0.080% weight by volume.
[0109] The present bioassay methods using amidine latex particles 22 call for a dilution 11 having a total dilution ratio 30 of microparticles 22 to dihydrogen monoxide in ranges of 1:10 to 1:400; and more preferably in a range of 1:20 to 1:150.
[0110] Amidine latex particles 22 which may meet the objectives of the present inventive bioassay methods may include high activity latex beads provided from Invitrogen™ when prepared according to the present inventive methods discussed herein.
[0111] Sulfate Microparticles
[0112] Another embodiment of the present invention employs sulfate microparticles 24 having a diameter of 110 nm in an 0.044% weight per volume dilution. The optical density of the dilution 11 was measured at 660 nm, for a value of 0.21.
[0113] Other sulfate microparticles 24 of the present invention range in diameter size 26 from 20 nm to 800 nm or more. The preferred range of sulfate particle 24 diameter 26 is 40 nm to 150 nm, a more preferred diameter 26 being in a range of 75 to 125 nm; and the most preferred diameter 26 being in a range of 90 nm to 110 nm.
[0114] According to some embodiments, sulfate microparticles 24 are in a dilution 11 in a range of 0.001% to 12% weight by volume, and more preferably in a dilution 11 having a range of 0.01% to 8% weight by volume, and most preferably a dilution 11 having a 0.016% weight by volume.
[0115] The present bioassay methods using sulfate microparticles 24 call for a dilution ratio 30 having a ratio of microparticles 24 to dihydrogen monoxide in ranges of 1:50 to 1:2000; more preferably a ratio in a range of 1:100 to 1:1000; and most preferably in a ratio of 1:500.
[0116] Sulfate latex particles 24 which may meet the objectives of the present invention may include high activity latex beads provided from Invitrogen™ when prepared according to the present inventive methods discussed herein.
[0117] Surface Free Microparticles
[0118] Another embodiment of the present invention employs surface free microparticles 20 having a diameter 26 of 96 nm in a dilution 11 having a 0.067% weight per volume 28. This dilution has a dilution ratio 30 of 1 to 150. The optical density 31 of the dilution 11 was measured at 660 nm, for a value of 0.21.
[0119] Other surface free microparticles 20 of the present invention range in diameter size 26 from 20 nm to 800 nm or more. The surface free microparticles 20 have a preferred range of diameter 26 of 40 nm to 150 nm, a more preferred diameter 26 being in a range of 75 to 125 nm; and the most preferred diameter 26 being in a range of 90 nm to 110 nm. According to some embodiments, surface free microparticles 20 are in a dilution 11 in a range of 0.001% to 2% weight by volume, and more preferably in a dilution 11 having a range of 0.01% to 0.2% weight by volume, and most preferably a dilution 11 having a 0.016% weight per volume.
[0120] The present bioassay methods using surface free microparticles 20 call for a dilution 11 having a dilution ratio 30 of microparticles 20 to dihydrogen monoxide 33 in ranges of 1:50 to 1:2000; and more preferably in a range of 1:100 to 1:1000.
[0121] Surface free particles which may meet the microparticles requirements of the present invention may include plain microparticles as provided from Varian Labs™, when prepared according to the present inventive methods discussed herein.
[0122] Carboxyl Microparticles
[0123] Other embodiments of the present invention employ carboxyl latex microparticles having a diameter of 103 nm in a 0.016% weight per volume solution. The optical density of the dilution 11 was measured at 660 nm, for a value of 0.08.
[0124] Other carboxyl microparticles 25 of the present invention range in diameter size 26 from 20 nm to 800 nm or more. The preferred range of carboxyl particle 25 diameter 26 is 40 nm to 150 nm, a more preferred diameter 26 being in a range of 75 nm to 125 nm; and the most preferred diameter being in a range of 90 nm to 110 nm.
[0125] According to some embodiments, carboxyl microparticles 24 are in a solution 28 in a range of 0.001% to 2% weight by volume, and more preferably in a solution 28 having a range of 0.005% to 0.1% weight by volume, and most preferably a dilution 11 having a 0.016% weight by volume.
[0126] The present bioassay methods using carboxyl microparticles 25 call for a dilution 11 having a dilution ratio 30 of microparticles 25 to diluent 33 in ranges of 1:50 to 1:2000; and more preferably in a range of 1:100 to 1:1000.
[0127] Carboxyl latex particles 24 which may meet the objectives of the present invention may include high activity latex beads provided from Invitrogen™ when prepared according to the present inventive methods discussed herein.
[0128] Drying Matrices
[0129] In general, the bioassay methods of the present invention can utilize most latex particle suspensions, plain or with functionalized surfaces. Some embodiments employ a matrix having reagent attenuators such as surfactants. Two such reagent attenuators which were tested include polysorbate-type nonionic surfactants and octylphenol ethoxylate surfactants. Polysorbate-type nonionic and octylphenol ethoxylate surfactants which may meet the objectives of the present invention may include surfactants provided by the Tween™ and Triton™ families when prepared according to the present inventive methods discussed herein.
[0130] Some of the drying matrices according to the present invention include carbohydrates, carbohydrate derivatives, and mixtures which create an environment which protect the particles from adverse temperatures and permit rapid re-hydration and uniform dispersal upon addition of fluid such as buffer, diluted sample, or other fluid reagent.
[0131] Carbohydrates, and their derivatives, are the preferred compounds used to dry the particles and provide stabilization during the drying process for the bioassay methods discussed herein. These reagents are prepared in water. However, low molarity buffers are also used in other embodiments, and examples of these include glycine and bicine. The percent concentration of the stabilizers range from 2 to 25% with a preferred range of 5 to 10%.
[0132] The compounds used for dry matrices include: glycine, bicine, sodium chloride, n-octenyl succinic anhydride, polyvinyl alcohol-polyethylene glycol graft copolymer, maltodextrins, α-(1,6)-linked maltotriose, α-D-glucopyranosyl-(1.fwdarw.1)-α-D-glucopyranoside, water-soluble glucose polymers obtained from the hydrolysis of starch with acid and/or enzymes in the presence of water, polysaccharide polymer, polyethylene glycols, polyethylene glycol (15)-hydroxystearate, povidones, sucrose, sorbitol, poly-oxyethylene esters of 12-hydroxystearic acid, and 1-O-alpha-D-glucopyranosyl-D-mannitol.
[0133] Publicly available versions of these compounds products which may meet the objectives of the present invention may include HiCap 100™, Kollicoat IR™, Maltrin 250™ Pullulan, Trehalose, Solutol™ Plus, and Solutol™. The preferred embodiment solutions are Lab 9101™, Maltrin 250, Trehalose™ and sucrose with the most preferred matrices being Maltrin™, sucrose, and isomalt. While for embodiments using dried sulfate microparticles, the preferred carbohydrate is sucrose or isomalt.
[0134] Liquid Matrices
[0135] The same particle suspensions described above for each of the dry matrixes may also be made in a more dilute form for ease in dispensing and aspiration using so called ‘liquid’ matrices. For example, when the dry matrix formulation consists of 25 uL of 1:18 sulfate latex with 10% sucrose, a similar liquid matrix has a reagent in the range of 50 uL of 1:9 sulfate latex with 5% sucrose. In other embodiments, the liquid matrix is formed of a lyse diluent.
[0136] Compounds employed in the liquid matrices of the present embodiments include: glycine, bicine, sodium chloride, n-octenyl succinic anhydride, polyvinyl alcohol-polyethylene glycol graft copolymer, maltodextrins, α-(1,6)-linked maltotriose, α-D-glucopyranosyl-(1.fwdarw.1)-α-D-glucopyranoside, water-soluble glucose polymers obtained from the hydrolysis of starch with acid and/or enzymes in the presence of water, polysaccharide polymer, polyethylene glycols, polyethylene glycol (15)-hydroxystearate, povidones, sucrose, sorbitol, poly-oxyethylene esters of 12-hydroxystearic acid, 1-O-alpha-D-glucopyranosyl-D-mannitol, polyethylene glycol (PEG), PEG 6K, PEG 12K, and PEG 20K, polysorbate-type nonionic surfactants, octylphenol ethoxylate surfactants, and/or simethicone diluted with water for injection grade purified water to a concentration supporting less than 15 second de-foaming performance in a USP Assay.
[0137] Publicly available versions of a select few of these compounds products which may meet the objectives of the present invention may include HiCap 100™, Kollicoat IR™, Lab 9101 ™; Maltrin 250™, Pullulan™, Trehalose™, Solutol Plus™, Solutol™, FoamAWAY™, and Sorbital™
[0138] Reagents
[0139] The bioassay methods of the present invention employ a variety of reagents 80 or activators. Compounds employed as activators of the present embodiments include: thrombokinase, thromboplastin, tissue thromboplastin factor III, platelet tissue factor, thrombokinase, thrombozyme, tissue factor, zymoplastic substance, ellagic acid, activated partial thromboplastin, thrombin, factor II, factor VII, factor I, factor X, factor XII, activated protein C, negatively charged phospholipids, calcium ions, alumina silicate clay, silicon oxide, silica, celite, and povidones.
[0140] Commercially available versions of a select few of these compounds and products which may meet the objectives of the present invention, when prepared appropriately, may include Kaolin™, Innovin™ Thromboplastin 82, APTT-XL 84, and Siemens™, Thrombin 86.
[0141] While stored for shipment prior to the actual bioassay, these reagents or activators may be in a dry state to ensure additional stability. Then during the assay, these reagents 80 may be diluted with diluent 90 such as DH.sub.2O, etc, at various amounts 94 in a range of 20 uL to 400 uL, more preferably in a range of 50 uL to 300 uL, and in a range of 50 uL to 100 uL, in various concentrations 96. Still other embodiments employ CaCl.sub.2) or other diluents which will be discussed with regard to the specific embodiments below.
[0142] Optical Density & Corrections
[0143] As initially discussed with regard to
[0144] Clot formation 124 is inferred and ‘detected’ based on the principle that in a medium in which fibrinogen is converted to fibrin, any light passing through this medium will be absorbed by the fibrin strands. Thus, as fibrin clot formation progresses over the passage of time, light absorption increases, resulting in a change 135 in the optical density 130.
[0145] For each of the bioassays discussed herein then, as discussed above, after collecting the sample, and mixing, light is transmitted from a source through the commixture 123. The transmitted light is then directed onto a light detector, which is positioned 180° incident to the source. The first corresponding electrical signal output from the photodetector of the first measurement 116′ uses optical detection to determine the levels of hemoglobin 125.
[0146] Light transmittance through the commixture 123 is again measured 116 by the photo detector for a predetermined time, which generates a second corresponding electrical signal output. Both this first and the second corresponding electrical signal outputs from the photo detector changes according to the detected light.
[0147] The signal output is processed via software through a series of algorithms to determine an associated clot point, clot initiation 132, and formation 134. In short, the change 135 in optical density 130 of the latex microparticle commixture 123 signal is used to indicate clot initiation 132 and formation 134.
[0148] Decreased Operational Procedure Elapsed Time
[0149] The present invention seeks to address several sources of laboratory error for coagulation detection procedures. As clot formation is dependent upon the passage of time, one of the largest sources of laboratory error for coagulation detection procedures is due to the passage of time between sampling 104 and measuring 116.
[0150] One of the principles of the present invention is to address the prior art's failure to address the increased number of errors which can occur due to the passage of time between sample taking 104 and detecting (measuring) 116. By pre-packaging the assay components in an all-inclusive cartridge 2 and providing pre-selected components for assay methodology, the present invention expedites the pre-detecting stages.
[0151] Another way in which the present invention achieves this goal is by providing a bioassay which is capable of achieving accurate results by using whole blood samples without the need to separate the red blood cells from the plasma before testing. Currently available point-of-care analyzers require the use of blood plasma as the sample. This requires separation of the red blood cells from the plasma in a blood sample before obtaining test results and further prolongs the period of time between the sample taking and testing.
[0152] One of the reasons current analyzers require blood plasma was discovered to be due to the inability of prior art automated systems and assays to provide self-correcting analysis. Levels of hemoglobin in the blood samples will have an impact upon the rate of clot initiation. The present inventors have found that failure to adjust the signal output of optical density to account for the variations in personal hemoglobin amounts can create errors in correctly identifying clot initiation and formation.
[0153] In order to address the errors of the prior art, with regard to this potential source of error, the present invention provides a bioassay method for auto-correction for hemoglobin. For the described clotting assay embodiment using whole blood, the optical density of the commixture is measured at a visible wavelength. Sequentially, the hemoglobin level is determined by measuring the sample optical density at another visible wavelength. The clotting time is then corrected using the hemoglobin measurement for the adjusted true plasma value of the sample. To illustrate the benefit of the advantages provided by this automatic correction, the effect of hemoglobin on prothrombin time INR values, with and without correction, is graphically illustrated in
[0154] Specifically, the graph in
[0155] The present invention facilitates the expansion of instrument capabilities to include multiple signal measuring devices such as, but not limited to, light emitting diodes (LED's) at multiple wavelengths. Measuring the optical density of the commixture to read the assay is preferably performed at a visible wavelength, in a range of 620 nm to 700 nm, more preferably between 650 to 680 nm, even more preferably between 658 nm and 668 nm, and most preferably at 660 nm. Measuring the optical density of the sample to read the hemoglobin levels is preferably performed at a visible wavelength, in a range of 500 nm and 550 nm, more preferably between 510 nm and 545 nm, even more preferably between 520 nm and 540 nm, and most preferably at 530 nm.
[0156] Table 1 shows the data which is graphically illustrated in
TABLE-US-00001 TABLE 1 HGB Effect on INR Sample HGB mg/dl INR 1 0 1.00 2 2.6 1.04 3 5.5 1.04 4 9.0 1.11 5 11.5 1.09 6 15.0 1.21 7 16.1 1.38 8 19.4 1.83 9 22.4 2.23
[0157] Table 2 shows the data which is also graphically illustrated in
TABLE-US-00002 TABLE 2 HGB effect on INR Corrected Sample HGB mg/dl INR 1 0 1.00 2 2.5 1.04 3 5.3 1.04 4 8.9 1.11 5 11.4 1.09 6 15.0 1.04 7 16.0 1.11 8 19.4 1.23 9 22.3 1.30
[0158] Next, shown in
[0159] Table 3 shows the data which is graphically illustrated in
TABLE-US-00003 TABLE 3 Effect of HGB on Plasma INR, Delta, Corrected Sample Plasma INR Delta INR Corrected Delta INR 1 0.96 0.05 0.05 2 0.96 0.21 0.08 3 0.96 0.39 0.11 4 0.96 0.82 0.24 5 0.96 1.21 0.29
[0160] Normalized Prothrombin Time/INR
[0161] It is to be understood that normalized INRs are employed in various embodiments of the bioassays of the present invention. Normalized prothrombin time INR are employed to address differences in the thromboplastins used which create variations in output. This INR correction measurement (or normalization) is developed from the prothrombin time, the sensitivity index of the thromboplastin, and the mean prothrombin time.
[0162] Specifically, in mathematical formulation, this normalization can be written as the following calculation:
INR=(PT/MT).sup.ISI
[0163] Where in the above formulation, INR stands for the normalization value; PT stands for the Prothrombin test time; ISI stands for the sensitivity index of the thromboplastin; and MT stands for the mean prothrombin time derived from 20 normal samples.
[0164] Specific Bioassays of the Present Invention
[0165] Turning now to
[0166] Bioassays Employing Tissue Thromboplastin
[0167] The results of different bioassays B1-B20 according to methods of the present invention employing varying matrixes for various microparticle dilutions are graphically illustrated in
[0168] B1-B4 Bioassays with BSA Coated Latex & Plain Microparticles
[0169] Turning now to
[0170] The first bioassay B1 employed a microparticle dilution 11 having microparticles 27 with bovine serum albumin (BSA) surface groups. The microparticles were diluted with 0.02% sodium azide in water by a ratio of 1 to 500, for a total microparticle concentration of 0.016%. The optical density of the dilution 11 was measured post dilution at 660 nm to have an optical density value of 0.08. This bioassay B1 further employed a matrix 40 having 0.17M glycine at pH 10.0, 1.0 M NaCl, and 1% simethicone diluted with water. This bioassay B1 was performed with a normal citrated whole blood sample 60.
[0171] In comparison, the second bioassay B2 had an identical protocol as bioassay B20 above, only B2 was performed with a microparticle dilution 11 which had microparticles 20 (without BSA surface groups). The selected reagents 80 for this bioassay were tissue thromboplastin and CaCl.sub.2).
[0172] As shown in
[0173] Also as shown in
[0174] To confirm this discrepancy, these bioassays B1, and B2 were repeated again, this time with abnormal blood samples, and for clarity sake, are designated as third and fourth bioassays B3, and B4, respectively.
[0175] As shown in
[0176] Also shown in
[0177] The protocols for the bioassays B1-B4 are provided in Table 16 below:
TABLE-US-00004 TABLE 4 Protocol for Bioassays B1-B4 Volume Component 390 uL Diluted particles 100 uL Selected Matrix 5 uL Sample 70 uL Reagent
[0178] Table 5 below shows the data of the optical density results using a kinetic mode at 660 nm over a period of time for the above described bioassays B1-B4 according to the present invention:
TABLE-US-00005 TABLE 5 Optical Density over Time Seconds B1 B2 B3 B4 0 0.1336 0.132 0.1328 0.1311 1 0.1366 0.1331 0.1334 0.132 2 0.1327 0.1327 0.13 0.128 3 0.1308 0.1338 0.1261 0.129 4 0.1367 0.1342 0.1234 0.1316 5 0.1377 0.1489 0.1226 0.1293 6 0.1363 0.1605 0.1211 0.1331 7 0.1346 0.1671 0.1218 0.1323 8 0.1342 0.1764 0.118 0.1331 9 0.1346 0.1865 0.1156 0.1315 10 0.135 0.1907 0.1149 0.13 11 0.1346 0.1896 0.1133 0.1315 12 0.1339 0.1911 0.1126 0.1273 13 0.1357 0.1927 0.1118 0.1257 14 0.1312 0.1961 0.1114 0.1242 15 0.135 0.1923 0.111 0.1211 16 0.1365 0.1933 0.1106 0.1203 17 0.135 0.193 0.1102 0.1199 18 0.1346 0.1892 0.1098 0.1184 19 0.1342 0.1942 0.1098 0.1172 20 0.1354 0.1908 0.1098 0.1168 21 0.1334 0.1919 0.1098 0.116 22 0.1334 0.1919 0.1098 0.1156 23 0.1338 0.1911 0.1098 0.1153 24 0.1342 0.1911 0.1098 0.1145 25 0.135 0.192 0.1095 0.1145 26 0.1354 0.192 0.1091 0.1145 27 0.1362 0.192 0.1087 0.1145 28 0.1362 0.1921 0.1087 0.1145 29 0.1365 0.1921 0.1087 0.1149 30 0.1369 0.1921 0.1083 0.116 31 0.1373 0.192 0.1083 0.1164 32 0.1373 0.192 0.1079 0.1176 33 0.1377 0.192 0.1079 0.1191 34 0.1377 0.192 0.1079 0.1207 35 0.1381 0.192 0.1079 0.1226 36 0.1381 0.192 0.1079 0.1253 37 0.1385 0.192 0.1079 0.1288 38 0.1385 0.192 0.1079 0.1331 39 0.1389 0.1921 0.1083 0.1385 40 0.1389 0.1921 0.1083 0.1439 41 0.1393 0.1921 0.1083 0.1501 42 0.1393 0.192 0.1083 0.1571 43 0.1396 0.192 0.1087 0.164 44 0.1396 0.192 0.1087 0.171 45 0.14 0.192 0.1087 0.1776 46 0.1404 0.192 0.1087 0.1838 47 0.1404 0.192 0.1087 0.1896 48 0.1408 0.192 0.1091 0.195 49 0.1408 0.1921 0.1091 0.1996 50 0.1412 0.1921 0.1091 0.2031 51 0.1412 0.1921 0.1095 0.2062 52 0.1416 0.192 0.1095 0.2093 53 0.142 0.192 0.1098 0.2108 54 0.142 0.192 0.1098 0.2128 55 0.142 0.192 0.1098 0.2143 56 0.1423 0.192 0.1102 0.2155 57 0.1427 0.192 0.1102 0.2166 58 0.1427 0.192 0.1102 0.2178 59 0.1431 0.192 0.1102 0.218 60 0.1431 0.192 0.1106 0.2185 61 0.1431 0.1921 0.1106 0.2186 62 0.1435 0.1921 0.111 0.2186 63 0.1439 0.1921 0.111 0.2188 64 0.1439 0.192 0.111 0.219 65 0.1443 0.192 0.1114 0.219 66 0.1443 0.192 0.1114 0.219 67 0.1447 0.192 0.1118 0.219 68 0.1451 0.192 0.1118 0.219 69 0.1451 0.192 0.1122 0.2188 70 0.1454 0.192 0.1126 0.219
[0179] B5-B10 Bioassays with Polyethylene Glycol Matrices
[0180] Turning now to
[0181] Specifically,
[0182] The optical density of the dilution in B5 was measured at 660 nm to have an optical density value 31 of 0.19. As shown in
[0183]
[0184] The optical density of the dilution was measured at 660 nm to have an optical density value of 0.21. As shown in
[0185] Turning next to
[0186] The optical density of the diluted solution was measured post dilution at 660 nm to have an optical density value of 0.21. As shown in
[0187]
[0188] This embodiment B8 employed a matrix 40 having 0.17M glycine 47, at pH 7.0, with 1.29M NaCl. The matrix 40 further comprising a carbohydrate derivative in the form of 10% Polyethylene glycol (PEG) 20K and 1% Tween20.
[0189] As shown in
[0190] Next,
[0191] As shown in
[0192] Then,
[0193] The optical density 31 of the dilution 11 was measured post dilution at 660 nm to have an optical density value 31 of 0.21. This embodiment further employed a matrix 40 having 0.17M glycine at pH 7.0, 1.29M NaCl, and 10% Polyethylene glycol (PEG) 20K.
[0194] As shown in
[0195] The protocol for all six embodiments B5-B10 listed above are shown in Table 4 below:
TABLE-US-00006 TABLE 6 Bioassays B5-B10 Component Protocol Volume Component 395 uL Diluted particles 50 uL Selected Matrix 5 uL Citrated whole blood 50 uL Reagent
[0196] The general methods for each of these bioassays B1-B6 were identical and generally prepared as discussed above with reference to
[0197] Table 5 shows the data of the corrected optical density results using a kinetic mode at 660 nm over a minute and a half for each of the above six described bioassay embodiments according to the present invention:
TABLE-US-00007 TABLE 7 Optical Density Against Time (secs) B5 B6 B7 B8 B9 B10 0 1.153 0.519 0.496 0.667 0.378 0.378 5 1.153 0.564 0.514 0.654 0.380 0.381 10 1.156 0.627 0.530 0.639 0.379 0.382 15 1.157 0.711 0.551 0.633 0.380 0.382 20 1.159 0.795 0.585 0.694 0.379 0.380 25 1.160 0.861 0.635 0.842 0.378 0.382 30 1.161 0.906 0.702 0.952 0.379 0.382 35 1.162 0.938 0.780 1.012 0.379 0.382 40 1.162 0.959 0.863 1.043 0.380 0.382 45 1.163 0.973 0.942 1.060 0.380 0.383 50 1.164 0.983 1.010 1.070 0.380 0.384 55 1.164 0.990 1.067 1.075 0.381 0.384 60 1.165 0.994 1.111 1.079 0.381 0.384 65 1.164 0.998 1.145 1.081 0.381 0.384 70 1.164 1.000 1.171 1.082 0.382 0.385 75 1.164 1.002 1.189 1.082 0.382 0.385 80 1.164 1.003 1.204 1.083 0.382 0.386 85 1.164 1.004 1.215 1.083 0.383 0.386 90 1.164 1.005 1.223 1.083 0.383 0.386
[0198] B11-B12 Bioassays with Simethicone Matrices
[0199] Turning now to
[0200] The optical density of the dilution 11 was measured post dilution at 660 nm to have an optical density value of 0.08. This bioassay B11 further employed a matrix 40 having 0.17M glycine at pH 10.0, 1.29M NaCl, and 1% simethicone diluted with water for injection grade purified water to a concentration supporting less than 15 second de-foaming performance in a USP Assay under the commercial identity of FoamAWAY™. This bioassay B11 was performed with a normal sample 60.
[0201] As shown in
[0202] In comparison,
[0203] The protocols for the bioassays B11, B12 are provided in Table 16 below:
TABLE-US-00008 TABLE 8 Protocol for Bioassays B11, B12 Volume Component 390 uL Diluted particles 100 uL Selected Matrix 5 uL Sample 70 uL Reagent
[0204] Table 9 below shows the data of the optical density results using a kinetic mode at 660 nm for the above described bioassays B11-B12 according to the present invention, over a minute for bioassay B12, and over 20 seconds for B11:
TABLE-US-00009 TABLE 9 Optical Density over Time Time (Seconds) B11 B12 0 0.1555 0.1691 1 0.1509 0.1582 2 0.1513 0.1563 3 0.1516 0.1547 4 0.1528 0.154 5 0.1563 0.1532 6 0.1625 0.152 7 0.1722 0.1516 8 0.1834 0.1513 9 0.1961 0.1516 10 0.207 0.1516 11 0.2155 0.152 12 0.2217 0.1524 13 0.2263 0.1524 14 0.2294 0.1516 15 0.2321 0.1516 16 0.2337 0.1516 17 0.2349 0.1516 18 0.2356 0.1516 19 0.236 0.1516 20 0.2364 0.1516 21 0.152 22 0.152 23 0.152 24 0.1524 25 0.152 26 0.152 27 0.152 28 0.1516 29 0.1524 30 0.1528 31 0.1536 32 0.1544 33 0.1547 34 0.1559 35 0.1574 36 0.1598 37 0.1629 38 0.1663 39 0.171 40 0.1768 41 0.1838 42 0.1915 43 0.2004 44 0.2097 45 0.2198 46 0.2298 47 0.241 48 0.2511 49 0.2604 50 0.2689 51 0.2767 52 0.284 53 0.2906 54 0.296 55 0.3006 56 0.3049 57 0.3088 58 0.3115 59 0.3142 60 0.3161 61 0.3177 62 0.3192 63 0.3204 64 0.3215
[0205] It is to be understood that while these optical density values are being shown here, these values are not normally presented to the user. Instead, according to the method discussed above, the clotting time is corrected using the hemoglobin measurement for the adjusted true plasma value of the sample. This corrected clotting time is then used to report a normalized INR as discussed above.
[0206] For example, for the abnormal blood bioassay B12 above, a first optical density measurement 116′ was taken in order to determine the hemoglobin content. The optical density detected at 530 nm was 1.5135, and this optical density value 140 was compared with a predetermined relationship 141 of OD values to known hemoglobin values in order to determine the specific hemoglobin level 142 present in the sample being analyzed. Again, although this level is not normally reported to the client or user, this analysis is graphically illustrated in
[0207] As discussed above with reference to
[0208] The system then uses this initial PT value 136 and retrieves the specific HGB level 142 as determined with reference to
CPT=PT*SQRT(C/HGB)
[0209] Where CPT is the corrected prothrombin time 138; PT is the uncorrected prothrombin time 136; C is a hemoglobin constant; and HGB is the specific hemoglobin level 142 associated with a specific sample 60.
[0210]
INR=(PT/MT).sup.ISI
[0211] Where for the above formula applied to data obtained for B12, PT stands for the prothrombin corrected test time 138 (50.1 seconds); ISI stands for the sensitivity index of the thromboplastin used (0.98 no associated units); MT stands for the mean prothrombin time derived from 20 normal samples (10.2 seconds); and INR stands for the normalization value 144 (4.8 no associated units). In general practice, only the corrected PT value (50.1 seconds) and INR value (4.8 no associated units) will be reported to the user.
[0212] B13-B14 Bioassays with Carboxyl Microparticle
[0213] Turning now to
[0214] The optical density of the diluted solution was measured post dilution at 660 nm to have an optical density value of 0.08. This bioassay B13 further employed a matrix having 0.17M glycine at pH 10.0, 1M NaCl, and 1% simethicone diluted with water for injection grade purified water to a concentration supporting less than 15 second de-foaming performance in a USP Assay under the commercial identity of FoamAWAY™. This bioassay B13 was performed with a normal sample 60.
[0215] As shown in
[0216] In comparison,
[0217] The protocols for the bioassays B13, B14 are provided in Table 10 below.
TABLE-US-00010 TABLE 10 Protocol for Bioassays B13, B14 Volume Component 390 uL Diluted particles 100 uL Selected Matrix 5 uL Sample 70 uL Reagent
[0218] Table 11 below shows the data of the optical density results using a kinetic mode at 660 nm for the above described bioassays B13-B14 according to the present invention, over a minute for bioassay B13, and over 20 seconds for B14:
TABLE-US-00011 TABLE 11 Optical Density over Time Time (Seconds) B13 B14 0 0.1304 0.1215 1 0.1284 0.1191 2 0.1288 0.118 3 0.1288 0.118 4 0.1292 0.118 5 0.1304 0.1184 6 0.1323 0.1187 7 0.1354 0.1187 8 0.14 0.1191 9 0.1458 0.1191 10 0.152 0.1191 11 0.1574 0.1187 12 0.1629 0.1187 13 0.1675 0.1187 14 0.1718 0.1191 15 0.1745 0.1191 16 0.1768 0.1203 17 0.1787 0.1211 18 0.1803 0.1207 19 0.1814 0.1199 20 0.1826 0.1195 21 0.183 0.1191 22 0.1191 23 0.1191 24 0.1191 25 0.1191 26 0.1191 27 0.1191 28 0.1191 29 0.1191 30 0.1191 31 0.1195 32 0.1195 33 0.1195 34 0.1199 35 0.1199 36 0.1203 37 0.1207 38 0.1207 39 0.1211 40 0.1218 41 0.1226 42 0.1238 43 0.1245 44 0.1261 45 0.128 46 0.13 47 0.1323 48 0.135 49 0.1381 50 0.1416 51 0.1451 52 0.1489 53 0.1532 54 0.1578 55 0.1621 56 0.1667 57 0.1714 58 0.1756 59 0.1799 60 0.1838 61 0.1872 62 0.1903 63 0.1934 64 0.1958 65 0.1977 66 0.1996 67 0.2012 68 0.2027
[0219] B15-B18 Bioassays with Differing Operating Temperatures
[0220] Typically, many bioassays according to the present invention are performed at physiologic temperatures, but this is not always the case. It is to be understood that in general, most temperatures can be applied to methods of the present invention. However, adjusting this variable with the bioassays discussed above will introduce potential variations such that the bioassay results will generally be altered. Thus, temperature variations should not be introduced without accounting for these variations, especially in clotting assays where accurate timing can impact clinical outcomes.
[0221]
TABLE-US-00012 TABLE 12 Protocol for Bioassays 15-18 Volume Component 395 uL Diluted particles 50 uL Selected Matrix 5 uL Citrated whole blood 50 uL Selected Reagent
[0222] Specifically, the bioassay B15 employed a microparticle dilution 11 having microparticles with amidine surface groups 22 having a diameter of 95 nm. At 0.080% weight per volume, this dilution 11 had microparticles 22 diluted with water by a ratio of 1 to 50. The optical density of the diluted solution was measured post dilution at 660 nm to have an optical density value of 0.19. This bioassay B15 employed a matrix 40 having 0.17M glycine at pH 7.0, 0.29M NaCl, and 10% Polyethylene glycol (PEG) 20K. This bioassay B15 was performed at a temperature of 22 C.
[0223] As shown in
[0224] Also seen in
[0225] As also shown in
[0226] Turning next to
[0227] The optical density 31 of the dilution 11 was measured at 660 nm to have an optical density value of 0.19. This bioassay B17 employed a matrix 40 having 0.17M glycine at pH 7.0, 0.29M NaCl, 10% Polyethylene glycol (PEG) 20K, and 1% Tween20. The bioassay B17 was performed at an operating temperature of 22 C.
[0228] As shown in
[0229] The second bioassay B18 according to the present invention, used a microparticle dilution which employed microparticles 22 with amidine surface groups having a diameter of 0.95 nm in a 0.080% weight per volume. The dilution 11 had a dilution ratio of 1 to 50. The optical density of the diluted solution was measured post dilution at 660 nm to have an optical density value of 0.19. This bioassay B18 also employed a matrix having 0.17M glycine at pH 7.0, 0.29M NaCl, 10% Polyethylene glycol (PEG) 20K, and 1% Tween20. However, unlike bioassay B17, the bioassay B18 was performed at an operating temperature of 37 C.
[0230] As also shown in
[0231] The general methods for each of these bioassays B15-B18 were identical and generally prepared as discussed above with reference to
[0232] Table 13 below shows the data of the corrected optical density results using a kinetic mode at 660 nm over minutes for each of the above described bioassays B15-B18 according to the present invention:
TABLE-US-00013 TABLE 13 Optical Density over Time TIME B15 B16 B17 B18 0 1.053 1.015 0.961 0.705 4 1.079 1.023 0.971 0.688 8 1.105 1.038 0.984 0.68 12 1.126 1.051 0.997 0.668 16 1.147 1.064 1.02 0.658 20 1.169 1.077 1.073 0.653 24 1.193 1.088 1.187 0.663 28 1.225 1.095 1.356 0.711 32 1.266 1.102 1.518 0.805 36 1.317 1.106 1.628 0.899 40 1.377 1.11 1.692 0.963 44 1.441 1.112 1.729 1.002 48 1.502 1.113 1.75 1.026 52 1.557 1.114 1.764 1.04 56 1.603 1.116 1.772 1.048 60 1.639 1.116 1.779 1.054 64 1.667 1.116 1.782 1.057 68 1.687 1.116 1.785 1.059 72 1.703 1.116 1.787 1.061 76 1.716 1.116 1.788 1.062 80 1.725 1.116 1.79 1.062 84 1.731 1.116 1.791 1.062 88 1.738 1.117 1.791 1.063 92 1.741 1.117 1.792 1.063 96 1.745 1.117 1.791 1.063 100 1.748 1.117 1.792 1.063 104 1.75 1.117 1.792 1.063 108 1.752 1.117 1.792 1.063 112 1.753 1.116 1.792 1.063 116 1.753 1.116 1.793 1.063 120 1.755 1.116 1.793 1.063
[0233] B19-B20 Bioassays for Monitoring Anticoagulant Use
[0234] Turning now to
[0235] Coumadin™ (also known as warfarin) inhibits Vitamin K synthesis and therefore inhibits the half-life of Factor VII. Factor VII levels are assayed and corrected in this graph using the prothrombin time test and dual wavelength correction as described herein.
[0236] As illustrated in
[0237] For both of these assays, B19 and B20, a microparticle dilution 11 employed microparticles 22 with amidine surface groups having a diameter 26 of 95 nm in a 0.080% weight per volume. These microparticle dilutions 11 were diluted with water by a ratio of 1 to 50. The optical density of the dilutions were measured post dilution at 660 nm to have an optical density value of 0.19.
[0238] As shown in
[0239] Also shown in
[0240] The protocol for the bioassays B19, B20 is provided in Table 14 below:
TABLE-US-00014 TABLE 14 Protocol for Bioassays 19, 20 Volume Component 345 uL Diluted particles 50 uL Selected Matrix 5 uL Sample 50 uL Tissue Thromboplastin (Innovin) w/CaCl2
[0241] The general methods for each of these bioassays B19-B20 were identical and generally prepared as discussed above with reference to
TABLE-US-00015 TABLE 15 Optical Density over Time TIME (secs) B19 B20 0 0.954 0.883 5 0.961 0.890 10 0.975 0.900 15 0.989 0.908 20 1.003 0.913 25 1.026 0.916 30 1.067 0.918 35 1.138 0.917 40 1.238 0.916 45 1.354 0.917 50 1.460 0.919 55 1.540 0.923 60 1.597 0.928 65 1.635 0.933 70 1.659 0.938 75 1.676 0.944 80 1.687 0.951 85 1.694 0.959 90 1.700 0.970 95 1.704 0.983 100 1.707 1.000 105 1.709 1.022 110 1.711 1.049 115 1.712 1.082 120 1.714 1.122 125 1.714 1.169 130 1.715 1.223 135 1.715 1.280 140 1.716 1.339 145 1.716 1.397 150 1.716 1.450 155 1.716 1.496 160 1.715 1.535 165 1.715 1.567 170 1.715 1.593 175 1.715 1.613 180 1.715 1.629
[0242] Bioassays Employing Thrombin
[0243] The results of different bioassays B21-B22 according to methods of the present invention employing varying matrixes for various microparticle dilutions are graphically illustrated in
[0244] B21-B22 Bioassays for Measuring Fibrinogen Levels
[0245] Turning now to
[0246] The protocols for the bioassays B15, B16 are provided in Table 16 below:
TABLE-US-00016 TABLE 16 Protocol for Bioassays 21, 22 Volume Component 390 uL Diluted particles 70 uL Selected Matrix 5 uL Sample (Plasma or Blood) 20 uL or 30 uL Thrombin time (TT) reagent
[0247] Specifically, these bioassays B21, B22 employed a microparticle dilution 11 having microparticles 24 with sulfate surface groups having a diameter 26 of 110 nm in an 0.2% weight per volume. Both bioassays B21, B22 employed a matrix 40 having 0.17M glycine at pH 10.0, 1.0M NaCl. The first bioassay B21 employed 30 uL of Siemens™ thrombin time (TT) reagent, and the second bioassay B22 employed 20 uL of Siemens™ thrombin time (TT) reagent.
[0248] Some thrombin inhibitors which may be used with the present inventive method are unfractionated heparins, low molecular weight heparins, and direct anti-thrombin oral anticoagulants including but not limited to hirudin, rivaroxaban, apixaban, dabigatran and argatroban. The general methods for each of these bioassays B21-B22 were identical and generally prepared as discussed above with reference to
[0249] As shown in
[0250] Also shown in
[0251] Table 17 shows the data of the optical density using a kinetic mode at 660 nm over three minutes for the first bioassay B21 with 30 uL Thrombin Reagent and for the second bioassay B22 with 20 uL Thrombin Reagent.
TABLE-US-00017 TABLE 17 Optical Density over Time Time (Secs) B21 B22 0 0.1334 0.1829 4 0.1349 0.1825 8 0.138 0.1863 12 0.1415 0.1897 16 0.1476 0.1942 20 0.1546 0.2025 24 0.1638 0.2124 28 0.1735 0.2241 32 0.1847 0.2369 36 0.1962 0.2509 40 0.2078 0.2657 44 0.2182 0.2793 48 0.2267 0.2921 52 0.2333 0.3031 56 0.2387 0.3122 60 0.2421 0.3201 64 0.2444 0.3262 68 0.246 0.3315 72 0.2475 0.3356 76 0.2483 0.339 80 0.2491 0.3421 84 0.2498 0.3443 88 0.2502 0.3462 92 0.2506 0.347 96 0.251 0.3477 100 0.2514 0.3481 104 0.2514 0.3485 108 0.2518 0.3489 112 0.2518 0.3489 116 0.2518 0.3489 120 0.2522 0.3492 124 0.2522 0.3492 128 0.2525 0.3489 132 0.2529 0.3489 136 0.2529 0.3489 140 0.2529 0.3489 144 0.2529 0.3489 148 0.2529 0.3489 152 0.2533 0.3492 156 0.2533 0.3489 160 0.2533 0.3489 164 0.2533 0.3485 168 0.2537 0.3485 172 0.2537 0.3485 176 0.2537 0.3485 180 0.2537 0.3485 184 0.2541 0.3485 188 0.2545 0.3485 192 0.2541 0.3485 196 0.2541 0.3485 200 0.2541 0.3481 204 0.2533 0.3485 208 0.2541 0.3481
[0252] Bioassays Employing Activated Partial Thromboplastin
[0253] The results of different bioassays B23-B27 according to methods of the present invention employing varying matrixes for various microparticle dilutions are graphically illustrated in
[0254] B23-B24 Bioassays for Intrinsic Pathway
[0255] Turning now to
[0256] Both bioassays B23, B24 employed microparticle dilutions 11 having 0.392% weight per volume microparticles 24 with sulfate surface groups having a diameter of 110 nm. A drying matrix as discussed above was employed having 20 uL of 0.005 M CaCl.sub.2). In another well, 100 uL of APTT-XL reagent was diluted with 150 uL of distilled water. The general methods for each of these bioassays B23-B24 were identical and generally prepared as discussed above with reference to
[0257] As shown in
[0258] As shown in
[0259] The protocol for the bioassays B23, B24 is provided in Table 19 below:
TABLE-US-00018 TABLE 18 Protocol for Bioassays 23, 24 Volume Component 30 uL Diluted particles 20 uL Selected Matrix 5 uL Sample 250 uL APTT-XL Reagent w/ DH20
[0260] Table 19 shows the data of the optical density using a kinetic mode at 660 nm over three minutes for the first bioassay B23 with normal control and for the second bioassay B24 with abnormal control:
TABLE-US-00019 TABLE 19 Optical Density over Time SECONDS B23 B24 3.7 0.5219 0.5041 7.7 0.5229 0.5004 11.7 0.5268 0.5033 15.7 0.5263 0.5053 19.7 0.5368 0.5024 23.7 0.5522 0.504 27.7 0.5702 0.5031 31.7 0.597 0.5036 35.7 0.6318 0.5031 39.7 0.6656 0.5034 43.7 0.7008 0.505 47.7 0.7333 0.5037 51.7 0.7598 0.5059 55.7 0.7862 0.5074 59.7 0.8061 0.5101 63.7 0.8187 0.5109 67.7 0.8336 0.5135 71.7 0.8508 0.5162 75.7 0.8596 0.5185 79.7 0.8682 0.5256 83.7 0.8774 0.5309 87.7 0.8833 0.5396 91.7 0.8886 0.5482 95.7 0.893 0.5575 99.7 0.8998 0.5699 103.7 0.9037 0.5827 107.7 0.9072 0.5947 111.7 0.9099 0.6116 115.7 0.9126 0.6264 119.7 0.9155 0.6423 123.7 0.9175 0.6569 127.7 0.9206 0.6746 131.7 0.9213 0.6862 135.7 0.921 0.7014 139.7 0.9259 0.7156 143.7 0.9248 0.7294 147.7 0.9252 0.7442 151.7 0.9278 0.7563 155.7 0.929 0.7695 159.7 0.9322 0.779 163.7 0.9313 0.7907 167.7 0.9318 0.8 171.7 0.9309 0.8114 175.7 0.9352 0.822 179.7 0.9353 0.8286 183.7 0.9349 0.8365 187.7 0.9347 0.8426 191.7 0.9371 0.8518 195.7 0.9369 0.8589 199.7 0.9382 0.8667 203.7 0.9369 0.8726 207.7 0.9369 0.8764 211.7 0.9371 0.885 215.7 0.9457 0.8864 219.7 0.941 0.8898 223.7 0.9415 0.8932 227.7 0.9425 0.898 231.7 0.9404 0.9054 235.7 0.9401 0.9074 239.7 0.9454 0.9097 241.7 0.942 0.9159
[0261] B25-B27 Bioassays for 1-Stage APTT Based Factor
[0262] Specifically,
[0263] Specifically,
[0264] Factors XII, XI, IX, VIII are measured directly with these assays. Additionally, Factors X, V, II are measured since they are involved in the common pathway cascade which lead to final clotting. Partial thromboplastin is formed from the sample by addition of common surface activators on Factor XII with the addition of calcium and phospholipid. Activators are, but not limited to, kaolin, celite, ellagic acid. One stage factor assays according to the present inventive method titer the samples individual factor level by comparing this level to a standard curve derived from dilutions of known factor deficient sample and a normal sample.
[0265] The general methods for bioassays B25, B26 were generally prepared as discussed above with reference to
[0266] As shown in
[0267] As shown in
[0268] Also shown in
[0269] The protocols for all three bioassays B25-B27 are provided in Table 20 below:
TABLE-US-00020 TABLE 20 Protocol for Bioassays B25-B27 Volume uL's Component 490 uL APTT activators in buffer, Ellagic acid 10 uL Sample 25 uL Microparticle Matrix 25 uL 0.02 M CaCl2 +10 uL known factor deficient plasma (B19 Only)
[0270] Table 21 below shows the data of the corrected optical density results using a kinetic mode at 660 nm over five minutes for each of the above described bioassays B25-B27 according to the present invention:
TABLE-US-00021 TABLE 21 Optical Density over Time TIME, Secs B25 B26 B27 0 0.042 0.33 0.177 10 0.035 0.321 0.171 20 0.034 0.315 0.169 30 0.034 0.312 0.172 40 0.091 0.315 0.169 50 0.235 0.316 0.182 60 0.317 0.314 0.312 70 0.342 0.312 0.451 80 0.349 0.312 0.518 90 0.352 0.311 0.539 100 0.353 0.314 0.546 110 0.353 0.334 0.548 120 0.354 0.358 0.55 130 0.354 0.384 0.55 140 0.354 0.418 0.55 150 0.354 0.461 0.55 160 0.354 0.508 0.55 170 0.354 0.557 0.55 180 0.353 0.606 0.55 190 0.353 0.652 0.55 200 0.353 0.693 0.55 210 0.353 0.73 0.55 220 0.353 0.76 0.55 230 0.353 0.784 0.55 240 0.353 0.803 0.55 250 0.353 0.817 0.55 260 0.353 0.827 0.55 270 0.353 0.834 0.55 280 0.354 0.838 0.55 290 0.354 0.842 0.55 300 0.354 0.844 0.55
LIST OF REFERENCED ELEMENTS
[0271] The following reference numbers are adhered to within the specification to refer to those referenced elements within the drawings of the present application.
TABLE-US-00022 1 Analyzer 61 Citrated blood 2 Cartridge 62 Whole blood 3 Barcode 63 Plasma 4 Fingerstick 64 Mix 5 sterilized pipette 65 Amount 6 Wells 68 Microparticle Mixture 7 Cuvette 70 Temperature 8 Sampler 80 Reagent/Activation 9 Main Packaging Agent 10 Microparticle Matrix 82 Thromboplastin 11 Microparticle Dilution 84 APTT 18 Functional group type 86 Thrombin 20 Plain 88 Ellagic Acid 22 Amidine 90 Diluent 24 Sulfate 92 CaCL2 26 Size 100 Method 28 % weight by volume 102 Selecting 30 dilution ratio Cartridge/Bioassay 31 Optical Density value 103 Scanning cartridge with 32 Amount analyzer 33 Diluent 104 Obtaining blood sample 40 Matrix 105 Performing fingerstick 42 Wet matrix 106 Removing capillary 44 Drying Matrix sampler provided with 46 Carbohydrates cartridge 47 Glycine 107 Touching sampler to 48 Amount blood, filling sampler 50 acidity with sample 52 NaCl 108 Replacing sampler in 54 PEG cartridge 56 TWEEN 109 Inserting cartridge 60 Blood Sample within analyzer 110 Automated Bioassay 126 Corrected Clot Time Process Steps 130 Optical density 112 Adding component 132 Clotting begins 114 Mixing/Stirring 134 Clotting ends Components 135 Change in absorption = 115 Incubating change in optical 116 Measuring density over time 118 Correcting 136 Uncorrected PT 119 Reporting Results 137 HGB relationship 120 Adjusting 138 Corrected PT 121 Mixture 140 OD value detected at 122 Solution 530 nm 123 Commixture 141 Predetermined 124 Optically Detected clot relationship of OD formation value to HGB 125 Optically Detected 142 Specific HGB Level Hemoglobin Levels
CONCLUSION
[0272] Although the preferred embodiments of the present invention have been described herein, the above description is merely illustrative. Further modification of the invention herein disclosed will occur to those skilled in the respective arts and all such modifications are deemed to be within the scope of the invention as defined by the appended claims.