Random and continuous-access immunoassays with chemiluminescent detection by Access automated analyzer.
The Access Immunoassay System is an automated random and continuous-access analyzer for use with heterogeneous enzyme immunoassays. The instrument stores refrigerated reagent packs for as many as 24 different immunoassays. Throughput is 50-100 tests per hour. One- and two-step, and sandwich and competitive formats, each with various incubation times, can be accommodated, and sample sizes can vary from 10 to 200 microL. A paramagnetic microparticle solid phase combines with a chemiluminescent substrate for signal generation. Within-run CVs for noninfectious disease assays were 2.0% to 9.2%; total CVs were 3.4% to 11.1%. Regression analysis of method comparison studies with established procedures yielded slopes of 0.84 to 1.12 and correlation coefficients > or = 0.94 for 12 of 14 assays (range 0.83-0.99). Compared with culture methods, the Access assay for Chlamydia in urogenital specimens demonstrated sensitivity, specificity, and positive and negative predictive values of 90%, 99.7%, 95%, and 99%, respectively.