Disclosed embodiments concern histochemical process compositions comprising at least one nanoparticle in an amount effective to reduce or substantially eliminate the average number of spots per slide that result from a sample staining protocol. The nanoparticle can be any of various nanoparticles, or combinations thereof, including metals, metal alloys, metal oxides, ceramics, functionalized metals or metalloids, and other miscellaneous nanoparticles, such as carbon nanoparticles and diamond nanoparticles. Typically, the nanoparticle concentration is from greater than zero to at least about 25 parts per million, more typically from about 2 parts per million to about 20 parts per million. Embodiments of a method for using process nanosolutions also are disclosed. One embodiment concerns applying a histochemical process composition to a sample, followed by performing a staining protocol on the sample. Particular embodiments concern automated histochemical processes comprising dispensing a nanosolution onto a sample using an automated system, heating the sample, and performing a sample staining process on the sample.

Methods are provided for end users of diagnostic measurement procedures to prepare quality controls having desired analyte recoveries, estimate recoveries of quality controls already prepared, and compare estimated and measured recoveries. To prepare a quality control containing a particular analyte, a desired recovery of a measurement procedure for the analyte can be scaled by a correlation factor to obtain a target nominal concentration of the analyte in the quality control. Alternatively, the nominal concentration of an analyte in a quality control can be scaled by a correlation factor to obtain a predicted recovery of a measurement procedure for the analyte. The correlation factors can be based on recovery data previously obtained using the measurement procedure and optionally one or more reference procedures, and can be calculated using regression analysis of these data. Each quality control can be prepared by dissolving a number of solid beads containing the analyte(s) of interest in a volume of base matrix.

A method of distinguishing a control solution from a sample in an electrochemical test sensor is performed. The method includes adding a control marker to the control solution. The control solution includes the control marker and analyte. The test sensor includes working and counter electrodes, and a reagent. A potential is applied to the test sensor to oxidize the control marker and the analyte. The resulting electrical current is measured. A potential is applied to the test sensor lower than the other potential in which the potential is sufficient to oxidize the analyte and not the control marker. The resulting electrical current is measured. Determining whether a control solution or a sample is present based on the measured electrical currents. To increase the measured current, a salt may be added to the control solution in an amount sufficient to increase the electrical current by at least 5% as compared to a control solution in the absence of a salt.

Provided are methods of detecting the presence or amount of a dihydroxyvitamin D metabolite in a sample using mass spectrometry. The methods generally comprise ionizing a dihydorxyvitamin D metabolite in a sample and detecting the amount of the ion to determine the presence or amount of the vitamin D metabolite in the sample. In certain preferred embodiments the methods include immunopurifying the dihydroxyvitamin D metabolites prior to mass spectrometry. Also provided are methods to detect the presence or amount of two or more dihydroxyvitamin D metabolites in a single assay.

The formulations, systems, and methods disclosed herein permit automated preparation of specimens (e.g., biological specimens) for examination. The disclosed formulations, systems, and methods provide fast, efficient, and highly uniform specimen processing using minimal quantities of fluids. The methods include at least a fixing phase for fixing a specimen to a substrate such as a microscope slide, a staining phase for staining the specimen, and a rinsing phase for rinsing the specimen. One or more of the fixing, staining, and rinsing phases include one or more agitation phases for distributing reagents evenly and uniformly across the specimen. The systems can be implemented as a standalone device or as a component in a larger system for preparing and examining specimens.

Provided are synthetic dendrimer calibrants for mass spectrometry. The calibrants are distinguished by their relative case and rapidity of synthesis, comparatively low cost, long shelf life, high purity, and amenability to batch synthesis as mixtures. The latter characteristic enables parallel preparation of higher molecular weight compounds displaying useful distributions of discrete molecular weights, thereby providing multi-point mass spectrometry calibration standards. Methods of making, tuning and using said calibrants are provided.

Embodiments of the invention include methods and compositions for producing standards for noninvasive prenatal genetic diagnostics and for the detection and monitoring of cancer. The compositions can include a plurality of different nucleosomal DNA fragments derived from either primary cells or cell lines and can include one or more synthetic oligonucleotides. The amount of the different nucleosomal DNA fragments can be varied so as to simulate naturally occurring cell free DNA samples obtained from the blood of the pregnant woman or naturally occurring cell free DNA samples obtained from the blood of cancer patients.

A device includes: a first portion configured to be grasped by the hand of the user, and a second portion defining a reservoir containing a control material, wherein the control material contains a target analyte in a known or predetermined concentration. A method of verifying the accuracy of an analyte monitoring device includes receiving a fluid sample, identifying the fluid sample as a control solution, and analyzing the fluid sample.

This invention is in the field of medical devices. Specifically, the present invention provides fluidic systems having a plurality of reaction sites surrounded by optical barriers to reduce the amount of optical cross-talk between signals detected from various reaction sites. The invention also provides a method of manufacturing fluidic systems and methods of using the systems.

This invention relates to a PCR fluorescence reference standard and to a method for manufacturing a PCR fluorescence reference standard. The PCR fluorescence reference standard comprises a fluorophore suspended in a thermoplastic polymer matrix. The PCR fluorescence reference standard of the invention has a greater shelf life than fluorophores dissolved in a solution and can advantageously be used to validate a fluorescence signal obtained in a thermal cycler.