Application of the Evidence MultiSTAT benchtop analyser to the fast (under 30 minutes), simultaneous, semi-quantitative determination of 29 drugs of abuse from one urine sample

Abstract

Biochip array technology allows for simultaneous screening of multiple drugs of abuse from a single human specimen and applied to the fully automated benchtop analyser Evidence MultiSTAT, provides rapid test results. Current technology compares the signal output of a sample to that of a cut-off, reporting a qualitative test result. Further advancement of the Evidence MultiSTAT technology allows a semi-quantitative result to be generated. Embedded software, preloaded with multiple calibration curves for each drug target, selects an optimal calibration curve by running two adjuster levels. Additionally, the software allows a user defined cut-off concentration to be selected enabling two samples to be analysed in parallel in under 30 minutes. The MultiSTAT DOA ToxPlex Urine array reports semi-quantitative test results for 29 drug targets simultaneously from a single sample. Simultaneous competitive chemiluminescent immunoassays ( n = 29) were employed. The assays were applied to the Evidence MultiSTAT biochip analyser, which processes a self-contained cartridge comprising all the components required for the assays. The system software selects the optimal calibration for each drug target from the database and processes and reports the multiple semi-quantitative results generated. The Graphical User Interface (GUI) presents the sample concentration for the 29 drug targets, the user defined cut-off concentration and whether the sample is classified as positive or negative in comparison to the selected cut-off. Inter-Assay Precision and Recovery performance were evaluated; three samples (−50%, cut-off and +50% samples) were assayed in triplicate per run for a total of 5 runs, n = 15. Resulting CVs were < 20% and recovery to target was within 70–130% for all 29 assays, confirming the suitability of the new semi-quantitative functionality. Application of the fully automated Evidence MultiSTAT allows for fast (under 30 minutes) semi-quantitative determination of 29 drug targets. The multiple results generated are displayed in an easy to visualise tabulated format and the system has the capacity to store and archive the results produced, which greatly aids accurate drug screening.