A novel approach for in-process monitoring and managing cross-contamination in a high-throughput high-performance liquid chromatography assay with tandem mass spectrometric detection.
Cross-contamination among wells of a high-throughput, high-density assay is a risk that cannot be detected or controlled by the performance of calibration standards and quality control samples. In the current practice, carryover and cross-contamination is detected only when analytes are detected in blank, zero, placebo, pre-dose samples, in a low standard or low quality control sample. There is no mechanism that allows bioanalytical scientists to determine if cross-contamination has occurred among other samples. As a result, erroneous results can be released to clients even though a batch meets the acceptance criteria. We tested a new approach that quantifies the cross-contamination of each sample and allows the scientist to make quality decisions with documentation. The approach will also detect carryover in over 90% of the wells. Briefly, two additional analytes were added as contamination markers. The markers were added to a multi-well plate alternatively creating a pattern of a checkerboard. The spiked multi-well plate was then used to perform the assay. If both markers were detected in a well, the sample was considered contaminated. The amount of the unexpected marker detected in a well measures the degree of contamination and may be used to make deactivation decisions. Depending on the relative impact of the contamination, a scientist can choose to tolerate the bias, reject the sample, reject the batch or raise the lower limit of quantitation for the batch. A guideline for rejection decisions is presented for discussion.
Chang
Min S
MS
Global Drug Analysis, Abbott Laboratories, Abbott Park, IL 60064-6126, USA. min.chang@abbott.com
Kim
Elaine J
EJ
El-Shourbagy
Tawakol A
TA
D015415:Biomarkers / Q000032:analysis; D002219:Carbamates / Q000097:blood; D002623:Chemistry Techniques, Analytical / Q000379:methods* / Q000592:standards; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004340:Drug Contamination; D005663:Furans; D006801:Humans; D061466:Lopinavir; D011744:Pyrimidinones / Q000097:blood; D011786:Quality Control; D015203:Reproducibility of Results; D019438:Ritonavir / Q000097:blood; D019258:Saquinavir / Q000097:blood; D012680:Sensitivity and Specificity; D013449:Sulfonamides / Q000097:blood; D053719:Tandem Mass Spectrometry / Q000379:methods*
D015415:Biomarkers; D002219:Carbamates; D005663:Furans; D011744:Pyrimidinones; D013449:Sulfonamides; D061466:Lopinavir; C095108:amprenavir; D019258:Saquinavir; D019438:Ritonavir