RESUMO
BACKGROUND: A high-throughput and highly efficient analytical platform for urine drug screening is critical in both clinical and forensic settings. Mass spectrometry (MS) has better sensitivity and specificity than conventional immunoassays (IA); however, not all laboratories have the necessary resources and workforce to operate MS. The goal of this study was to evaluate a multidrug biochip with 20 discrete testing regions (DTRs) for high-throughput urine drug screening (UDS). METHODS: The Randox DOA Ultra Urine (DOAULT URN) biochip employs chemiluminescent IA to detect various analytes, including stimulants, hallucinogens, sedatives, narcotics, and dextromethorphan. The verification included the evaluation of the limits of detection (LOD), stability of calibrators and controls, cross-reactivity, carryover, interference, and overall performance. RESULTS: LODs < quality control low for each DTR. The reconstituted calibrators were stable for up to 2 weeks at -20°C. Controls were stable for 4-6 hours at 22-25°C, with <20% within-day and ≤23% between-day imprecision. The accuracy of the controls (%bias) was within ±20% of the target concentration, except for dextromethorphan at -23.8%. No interference was observed with common over-the-counter medications. No carryover was detected in the high-concentration samples. Satisfactory cross-reactivity (≥50%) with known analytes produced presumptive positive results, with readings higher than the proposed decision points. The overall biochip performance of 165 confirmed samples showed 98.0% sensitivity, 96.9% specificity, and 97.5% efficiency. CONCLUSIONS: The DOAULT URN biochip is a multidrug analyte IA capable of detecting dozens of parent drugs and their metabolites in urine. It offers clinical and forensic laboratories an alternative UDS tool with LODs comparable to those of MS.