Optimization of EMIT reagent system using a COBAS-BIO centrifugal analyzer.

An optimized method for application of the EMIT reagent system to a COBAS-BIO centrifugal analyzer was developed to minimize reagent consumption while maintaining good precision and accuracy. Forty-one serum samples, previously analyzed for theophylline by HPLC, were assayed using the modified protocol on the COBAS-BIO centrifugal analyzer. Regression analysis of the results obtained from both methods yielded the following equation: y = 1.10x + 0.01, r = 0.964 (x = HPLC, y = COBAS-BIO centrifugal analyzer, EMIT). The COBAS-BIO centrifugal analyzer and EMIT methodology provided an efficient, inexpensive, and relatively effortless approach to drug monitoring in the routine clinical laboratory.