Sample collection device

Abstract

Provided herein is technology relating to collecting and preparing samples. For example, the technology relates particularly, but not exclusively, to devices, systems, and kits that allow a subject to collect and prepare a sample for analysis.

Claims

1. A method of collecting a metered sample of stool, the method comprising: I) providing a collection device comprising: a) a body comprising a sample collection chamber bounded on a distal end by a penetrable seal and bounded on a proximal end by a septum comprising an aperture, the penetrable seal being penetrable by a pipette tip or needle; b) a flexible sampling rod comprising a proximal portion and a distal portion, the sampling rod adapted to fit through and seal the aperture when the distal portion is in the sample collection chamber, wherein the distal portion comprises: i) an asymmetrical beveled tip at a distal end, the beveled tip having an apex at the circumference of the flexible sampling rod and configured to bend the flexible sampling rod away from collisions and/or to deflect collisions with an inserted pipette tip or needle; and ii) one or a plurality of metering ridges; II) contacting stool with the distal portion of the sampling rod to cover one or more of the one or a plurality of metering ridges with the stool; III) inserting the distal end of the sampling rod through the aperture in the septum, such that the aperture in the septum is sealed by the sampling rod and a metered sample of the stool has entered the sample collection chamber.

2. The method of claim 1, wherein the collection device comprises a solution in the sample collection chamber for preserving the metered sample of the stool.

3. The method of claim 2, wherein the solution comprises Tris buffer, bovine serum albumen, polysorbate 20, sodium azide, sodium chloride, ethylenediaminetetraacetic acid, and gentamicin.

4. The method of claim 1, wherein a cap is attached to the proximal end of the sampling rod, wherein the cap is configured to engage a proximal end of the body of the collection device, the method further comprising after step III): IV) engaging the cap with the proximal end of the body.

5. The method of claim 4, wherein the cap and the proximal end of the body have mated threads that engage with each other to secure the cap to the proximal end of the body of the collection device.

6. A method of collecting a metered sample of stool from a subject, the method comprising: I) providing to the subject a collection device comprising: a) a body comprising a sample collection chamber bounded on a distal end by a penetrable seal and bounded on a proximal end by a septum comprising an aperture, the penetrable seal being penetrable by a pipette tip or needle; b) a flexible sampling rod comprising a proximal portion and a distal portion, the sampling rod adapted to fit through and seal the aperture when the distal portion is in the sample collection chamber, wherein the distal portion of the sampling rod comprises: i) an asymmetrical beveled tip at a distal end, the beveled tip having an apex at the circumference of the flexible sampling rod and configured to bend the flexible sampling rod away from collisions and/or to deflect collisions with an inserted pipette tip or needle; and ii) one or a plurality of metering ridges; and wherein the proximal portion of the sampling rod is attached at a proximal end to a cap wherein, when the sampling rod is fitted through and sealing the aperture with the distal portion of the sampling rod in the sample collection chamber, the cap engages with a proximal end of the body to form a sealed collection device; and II) receiving from the subject the sealed collection device containing a metered sample of stool in the sample collection chamber.

7. The method of claim 6, wherein the cap and the proximal end of the body have mated threads that engage with each other to secure the cap to the proximal end of the body.

8. The method of claim 6, wherein the collection device comprises a solution in the sample collection chamber for preserving the metered sample of the stool.

9. The method of claim 8, wherein the solution comprises Tris buffer, bovine serum albumen, polysorbate 20, sodium azide, sodium chloride, ethylenediaminetetraacetic acid, and gentamicin.

10. The method of claim 8, wherein the metered sample and the solution form a suspension, and wherein the method comprises a step of withdrawing at least a portion of the suspension from the sealed collection device.

11. The method of claim 10, wherein withdrawing the suspension comprises penetrating the penetrable seal.

12. The method of claim 11, wherein the penetrable seal is penetrated with a pipette tip or needle.

13. The method of claim 6, further comprising providing to the subject packaging for transporting the sealed collection device, and wherein the receiving comprises receiving the packaging containing the sealed collection device containing a metered sample of the stool in the sample collection chamber.

14. The method of claim 6, wherein providing to the subject the collection device further comprises providing an instruction for collecting the metered sample of stool using a method comprising: I) contacting the stool with the distal portion of the sampling rod to cover one or more of the one or a plurality of metering ridges with the stool; II) inserting the distal end of the sampling rod through the aperture in the septum, such that the aperture in the septum is sealed by the sampling rod and the metered sample of the stool has entered the sample collection chamber.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other features, aspects, and advantages of the present technology will become better understood with regard to the following drawings:

(2) FIG. 1 is a side view of an embodiment of the device provided herein.

(3) FIG. 2 is a side section view of an embodiment of the device provided herein, comprising a body (1) and a cap (12), the body (1) comprising proximal chamber (11) and a distal sample collection chamber (10). The distal sample collection chamber (10) is bounded on a distal end by a penetrable seal (2) on a sealing surface (13) on the body (1), and is bounded on a proximal end by a septum (3), the septum comprising an aperture (4). The cap (12) is affixed to the proximal end of a sampling rod (5) adapted to fit through and seal the aperture (4). The sampling rod (5) comprises a proximal portion (6), and a distal portion (7) having an angled tip (8) at the distal end and at least one metering ridge (9) near the distal end.

(4) FIG. 3 is an isometric section view of an embodiment of the device provided herein.

(5) FIG. 4 is an exploded view of an embodiment of the device provided herein.

(6) FIG. 5 is in a side view of an embodiment of the body component.

(7) FIG. 6 is a side section view of an embodiment of the body component.

(8) FIG. 7 is an isometric section view of an embodiment of the body component.

(9) FIG. 8 is a side view of an embodiment of the sampling rod component.

(10) FIG. 9 is a side section view of an embodiment of the sampling rod component.

(11) FIG. 10 is an isometric section view of an embodiment of the sampling rod component.

(12) FIG. 11 is an isometric view of an embodiment of the sampling rod component.

DETAILED DESCRIPTION

(13) Provided herein is technology for acquiring a sample (e.g., a fecal sample) and preparing a suspension of the sample for analysis (e.g., a fecal immunochemical test). The device comprises two ends—one (proximal) end that is accessed by the user who acquires the sample and introduces it into the device for preservation and storage and the other (distal) end that is accessed by a human or automated tester for removing a portion of the resuspended sample for analysis. The features and components described herein combine to provide such functionality in a simple device that produces preserved and stable metered fecal samples for analysis (e.g., by FIT).

Definitions

(14) To facilitate an understanding of the present technology, a number of terms and phrases are defined below. Additional definitions are set forth throughout the detailed description.

(15) As used herein, “a” or “an” or “the” can mean one or more than one. For example, “a” widget can mean one widget or a plurality of widgets.

(16) As used herein, a “penetrable seal” hermetically closes an opening of a chamber or enclosed space while the component is intact and is capable of being pierced or breached (e.g., by a needle or a pipette tip) to allow access to the contents sealed inside.

(17) As used herein, the term “metered” means having a reasonably reproducible measured quantity.

Embodiments of the Technology

(18) Although the disclosure herein refers to certain illustrated embodiments, it is to be understood that these embodiments are presented by way of example and not by way of limitation.

(19) As shown by FIGS. 1-11, the device comprises as principal components a sampling rod, a body comprising a septum and a penetrable seal, and a solution. Embodiments of the device, particularly in reference to the interactions of these and other components, are described below.

1 Sampling Rod

(20) The device comprises as a first component a sampling rod (5). As illustrated, e.g., in FIG. 2, the sampling rod (5) comprises a distal portion (7) and a proximal portion (6). In some embodiments the sampling rod is approximately 2.5 inches long. In certain preferred embodiments, the sampling rod is substantially circular in cross section for most of its length.

(21) The proximal portion (6) of the sampling rod (5) is adapted for manipulation by a user and the distal portion (7) is adapted to acquire a metered sample. In some embodiments, a cap (12) is attached to the proximal end. In preferred embodiments, the cap (12) is adapted to mate with and close the proximal end of the body (1) (see below), for example, by mated threads on the cap (12) and body (1), by a snap closure, by a friction seal, or by other closures by which a cap securely closes a vessel to seal contents inside the vessel. In some embodiments, mated threads on the cap (12) and body (1) provide for securing the sampling rod (5) with a half-turn screw fit to the body (1). In some embodiments, the cap (12) comprises textured features that facilitate gripping and manipulating the sampling rod (5) by the user.

(22) One or more metering ridges (9) is/are located near the tip (distal end) of the distal portion (7) of the sampling rod (5) (see FIGS. 2, 4, 5, and 8). In certain embodiments, each metering ridge is shaped like the frustum of a cone (e.g., a right circular cone, truncated by a plane parallel to the base). In preferred embodiments, the frustum has its base facing toward the proximal end of the sampling rod (5), and has its axis aligned with the longitudinal axis of the sampling rod. As is seen in the embodiments shown in the figures (e.g., FIG. 8), in some embodiments a series of axially aligned frusta are joined in some embodiments to make notched depressions in the distal end of the sampling rod (e.g., to form a serrated, saw tooth, or fish scale structure). In preferred configurations, the bases of the frusta have radii approximately the same as the radius of the distal portion of the sampling rod; thus, the radii of the tops of the frusta are smaller than the radius of the sampling rod.

(23) The notched depressions of the metering ridges provide a structure within which to acquire a metered sample (e.g., a sample of approximately 20 milligrams). In use, rubbing and/or scraping the area comprising the metering ridges (9) on the stool to be sampled captures a mass of stool that covers the metering ridges (9) on the distal portion of the sampling rod. Furthermore, the metering ridges provide an effective way to collect a reasonably reproducible and defined volume and/or mass (e.g., approximately 20 milligrams) of feces for the sample. In particular, feces captured in the notched depressions remain associated with the sampling rod when the sampling rod is passed through a hole or aperture that is approximately the same radial size as the radius of the distal portion (7) of the sampling rod (5) (e.g., the aperture of the body septum as described below). The metering ridges comprise notched depressions having a defined volume for collecting a sample of a defined mass. Thus, when excess feces that is not present in the space defined by the notched depressions is scraped or rubbed from the sampling rod, e.g., by passage through an aperture, the feces remaining in the notched depressions has a volume defined by the size and shape of the notched depressions.

(24) The sampling rod (5) is adapted to be inserted into the body (1), and, in particular, the sampling rod (5) is designed to fit through the body septum aperture, (a feature described in more detail below). Moreover, when inserted into the body (1), the sampling rod (5) is designed to seal the aperture (4) at the end of travel and thus seal the body sample collection chamber (10) (see below). In some embodiments, the device is designed to provide a seal at the aperture (4) that holds a minimum of 30 psi when internally pressurized with air. In particular, the sampling rod (5) comprises a proximal portion (6) and a distal portion (7). In certain preferred embodiments, the distal portion (7) has a radius that is smaller than the radius of the proximal portion (6) (see, e.g., the embodiment shown in FIGS. 2 and 8). Furthermore, in relation to the aperture (4) in the body septum (3), the radius of the distal portion (7) of the sampling rod (5) is smaller than the radius of the aperture (4) (e.g., very slightly smaller, such that excess feces is removed from the sampling rod (5) when the distal portion (7) passes through the aperture (4)), and the radius of the proximal portion (6) is larger than the radius of the aperture (4). Consequently, the junction of the proximal and distal portions of the sampling rod (5) forms a plug or stopper that seals the aperture (4) (and thus the sample collection chamber (10)) when the sampling rod (5) is substantially fully inserted into the body at the end of travel. In some embodiments, tightening the cap (12) onto the body (1) (e.g., by screwing) further secures the seal.

(25) In some embodiments, the distal tip (8) of the sampling rod is angled or beveled (see, e.g., (8) in the embodiments shown in FIGS. 2 and 8). When inserting a pipette tip or syringe needle into the distal end of the body (1) to withdraw an aliquot of the feces suspension (as described below), the tip or needle may sometimes collide with the sampling rod and consequently interrupt or otherwise compromise the withdrawal of the proper amount and/or damage the apparatus or machine used to withdraw the sample. While this is problematic for a human operator, a trained human can realize what has occurred and makes another attempt at withdrawing the proper volume as an aliquot for assay. However, in an automated setting wherein an autonomous robot or semi-autonomous system retrieves the aliquot, collision with the sampling rod may damage the machine and/or cause improper sampling. Consequently, an improper volume will be tested and produce an inaccurate and potentially misleading result (e.g., a false negative or false positive result). To minimize or eliminate such episodes, embodiments of the technology provide a sampling rod (5) with an angled tip (8) that, when inserted into the body (1) after acquiring a fecal sample, deflects collisions with an inserted pipette tip, syringe needle, or other implement inserted through the penetrable seal (2) e.g., to withdraw an aliquot of the fecal suspension. Moreover, in some embodiments, the sampling rod is made from a material that is flexible, so that it flexes or bends out of the way when a collision occurs. Deflection and/or flexing minimizes or eliminates the mechanical stress and trauma to the sampler and/or improper sampling that is associated with collisions and thus aids in maximizing the reproducibility of sampling and testing.

2 Body

(26) The device comprises as another component a body (1). The body comprises a proximal chamber (11) and a distal sample collection chamber (10) (see, e.g., FIG. 2). The two chambers are separated by a septum (3), and the septum comprises an aperture (e.g., a hole, (4)) near its center that is just slightly large enough to allow passage of the distal portion (7) of the sampling rod (5) through it (see FIGS. 2 and 3). The long axis of the body has a length appropriate to contain the entirety of the sampling rod when the sampling rod is fully inserted into the body. In some embodiments, the outer diameter of the body is approximately 14 millimeters. When the sampling rod (5) is substantially fully inserted into the body (1) (e.g., at its end of travel into the body), the metering ridge (9) (and substantially all the acquired sample present within the notched depressions of the metering ridge) is located completely within the sample collection chamber (10) and thus is exposed there to any solution contained therein (see below). In preferred embodiments, the device is designed such that the sample contained within the metering ridge (9) contacts the solution in the sample collection compartment regardless of the orientation of the device.

(27) The sample collection chamber (10) is bounded laterally by the body wall and on the proximal and distal ends by the septum (3) and by a penetrable seal (2) (see below, and FIG. 2, e.g.), respectively. In some embodiments, the proximal end of the body (1) is adapted to mate with a cap (12) attached to the proximal end of the sampling rod (5), for example, by means of mated threads on the cap and body (e.g., for securing the cap and sampling rod to the body with a half-turn screw), a snap closure, a friction seal, or other features by which a cap securely closes a vessel. See, e.g., body (1) and cap (12) in FIG. 2.

(28) The body (1) is open on the distal end, e.g., the body comprises a hole on the distal end. The body (1) comprises a sealing surface (13) that is adapted to accept a penetrable seal on the distal end to cover the hole. See, e.g., sealing surface (13) in FIGS. 2, 3, and 6. In some embodiments the penetrable seal (2) is recessed. In certain preferred embodiments, the penetrable seal (2) is recessed approximately 0.125 inches with respect to the distal end of the body. In some embodiments the distal end of the body is adapted to accept a removable cover or cap, e.g., a pop-off cap, to protect the penetrable seal. In preferred embodiments, the diameter of the hole in the distal end of the body (1) is smaller than the width of the distal end of the body so that a ring of material is present on the distal end surrounding the hole, providing a surface on which to apply a penetrable seal (2). See, e.g., the sealing surface (13) in FIGS. 2 and 7. By affixing the penetrable seal (2) to the distal end of the body over the hole, the penetrable seal (2) hermetically closes the distal end of the body.

(29) The sample collection chamber (e.g., sample collection chamber (10) in FIGS. 2 and 3) is adapted to hold a solution (e.g., the solution described below). In some embodiments, the sample collection chamber is adapted to hold a solution having a volume of approximately 2 milliliters. In some embodiments, when the sample collection chamber contains a solution, sample introduced into the chamber on the sampling rod is covered with the solution regardless of the orientation of the device. Furthermore, in certain preferred embodiments, when the sample collection chamber contains a solution, the sample collection chamber also holds a volume of air that allows for mixing of the sample with the solution. When the penetrable seal is secured to the distal end and the sampling rod is substantially fully inserted into the body to seal the aperture (e.g., at the end of travel for the sampling rod into the body), the solution is contained within the sample collection chamber such that it will not leak from the sample collection chamber. In some embodiments, the seal formed at the aperture holds a minimum of 30 psi when the device is internally pressurized with air. In some embodiments of the technology provided herein (e.g., embodiments of kits), the device is supplied to the end user in this type of a configuration (e.g., preloaded with solution and sealed by the sampling rod and penetrable seal).

3 Penetrable Seal

(30) A third feature of the device is a penetrable seal. In preferred embodiments, the penetrable seal (2) is affixed to the distal end of the body to cover the hole on that end, thus sealing the sample collection chamber (10) on that end (and thus preventing the escape of any solution and/or sample that is contained inside). See, e.g., penetrable seal (2) in FIGS. 2, 3, and 4. The penetrable seal (2) is affixed to the body by any suitable means that adequately seals the distal end of the body, e.g., by an adhesive, crimping, friction, physical incorporation into the body when the body is molded, etc. For example, in some embodiments the penetrable seal is affixed to the body such that it provides a seal of the distal end that holds a minimum of 30 psi when the device is internally pressurized with air.

(31) Furthermore, the penetrable seal is made from a material that can be penetrated, e.g., by a syringe needle or a pipette tip, to allow access to the sample collection chamber by a human user or an automated or semi-automated robot or other machine. Materials that are appropriate for the penetrable seal include, but are not limited to, foil, paper, rubber, plastic, and wax. The penetrable seal is made from a material that is chemically and biochemically compatible with the solution and samples that contact the device. The penetrable seal is strong enough to contain a solution securely (e.g., without leaking (e.g., the seal holds a pressure of 30 psi when internally pressurized with air)) within the sample collection space, while also being penetrable upon application of a low to moderate amount of force by a needle or pipette tip (e.g., a 1-milliliter pipette tip) pressed against the penetrable seal by a user, machine, or robot. For example, in some embodiments the penetrable seal comprises a laminated foil comprising a foil layer of approximately 0.001 inches and a polyester layer of approximately 0.005 inches. Such a foil product is available from commercial vendors (e.g., Hi-Tech Products). In some embodiments, other products are used that are suitable to meet the shelf life and sealing requirements.

4 Solution

(32) The device comprises a solution in the sample collection chamber. In certain embodiments, the solution comprises Tris buffer, bovine serum albumin, Tween-20, sodium azide, sodium chloride, EDTA, and gentamicin. In preferred embodiments, the solution comprises the following components approximately in the indicated amounts and/or concentrations: 20 mM Tris buffer (pH 7.4) 10% bovine serum albumen 0.10% Tween-20 0.095% sodium azide 140 mM sodium chloride 10 mM EDTA 15 μg/ml gentamicin

(33) The solution comprises components to break up, solubilize, and/or suspend the sample such that withdrawal of a portion provides an aliquot suitable for analysis. In addition, the solution comprises components to stabilize, preserve, and/or protect the resulting suspension so that the analytes to be tested (e.g., globin) do not degrade or become damaged between the time the sample is acquired and the time the sample is tested. The solution thus helps to ensure that the analysis of the sample (e.g., a FIT) accurately reflects the analytes (e.g., globin) present in the sample when the sample was acquired.

5 Materials

(34) The body (1), sampling rod (5), and cap (12) are made from a material that provides structural soundness to the device and that is chemically and biochemically compatible with the solution and samples that contact the device. Embodiments of the device are made from plastics such as, e.g., polypropylene, polyethylene, polystyrene, and polytetrafluoroethylene. The sampling rod (5) is made from a material that provides sufficient strength to the rod for collecting from relatively rigid samples. For example, in some embodiments the sampling rod is made from an opaque polypropylene and in some embodiments the sampling rod is made from a filled polypropylene. In some embodiments, the sampling rod is flexible and is thus made from a material that provides the appropriate flexibility, e.g., a flexible polypropylene. In some embodiments, the cap (12) and the body (5) are made of the same material. Moreover, in some embodiments the body is made from a transparent polypropylene. Different materials may be suitable for different applications and sample types, and, in some embodiments, the body and sampling rod are made from the same material and in some embodiments the body and sampling rod are made from different materials. In some embodiments, the materials and composition of the solution are chosen to provide a shelf-life for the device of approximately 2 years.

6 Use of the Device

(35) The device is designed to provide an easy way to collect and produce fecal samples for analysis such as FIT. Accordingly, it is designed for use by both the sample taker and the sample tester. The sample taker may be, in some uses of the device, a person who does not have medical or clinical training, and thus the device is easy to use for such lay users in acquiring the sample. Thus, in some embodiments the body is composed of opaque material, or is covered, e.g., with a label, such that the interior components (e.g., the proximal and distal chambers, the septum, and the inserted sampling rod) are substantially blocked from view of a user, e.g., to avoid confusion regarding the proper use of the device.

(36) At the same time, the device is designed within the appropriate tolerances and with a design that allows for precise and accurate analysis of the sample by a human or machine tester. Generally, the device will be provided to the sample provider in an assembled form—e.g., the sample collection chamber is filled with a volume of solution, the distal end of the body is sealed with the penetrable seal, and the sampling rod is fully inserted into the body such that the aperture is sealed.

(37) Upon producing a stool, the sample provider removes the sampling rod (5) from the body (1) and scrapes or spears the stool with the sampling rod (5) to cover with stool the distal portion (7) of the sampling rod (5) comprising the metering ridge (9). The sampling rod (5) is then placed back into the body (1) by inserting the sampling rod (5) through the aperture (4) and securing the cap (12) to the body (1) (e.g., by screwing it onto the body by means of mated threads). When the sampling rod (5) is inserted through the aperture (4) in the body (1), stool not present in the notched depressions of the metering ridge (9) (e.g., excess stool) is rubbed and/or scraped from the sampling rod such that it remains in the proximal chamber (11) and outside the sample collection chamber (10). Consequently, only the feces associated with the metering ridge (9) is introduced into the sample collection chamber (10) and the solution present therein. The solution then acts to break up, solubilize, and/or suspend the sample. In addition, the solution comprises components to stabilize, preserve, and/or protect the suspension. The user then returns the device to a laboratory, clinic, or other location for analysis. In some embodiments, the device is designed to be appropriate for return by mail.

(38) Next, the testing facility retrieves a portion of the feces suspension for analysis (e.g., by FIT). A user or machine penetrates the penetrable seal (2) (e.g., by a syringe needle or a pipette tip) to withdraw an aliquot of the suspension. The device is designed for manipulation by a human tester, an autonomous machine or robot, and/or a semi-autonomous machine, as appropriate for the analysis. After the required aliquot of the suspension is withdrawn, the device and remaining fecal sample suspension may then by discarded as appropriate.

(39) All publications and patents mentioned in the above specification are herein incorporated by reference in their entirety for all purposes. Various modifications and variations of the described compositions, methods, and uses of the technology will be apparent to those skilled in the art without departing from the scope and spirit of the technology as described. Although the technology has been described in connection with specific exemplary embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention that are obvious to those skilled in pharmacology, biochemistry, medical science, or related fields are intended to be within the scope of the following claims.