ABSTRACT
The use of AMPLILINK version 1.0 software was evaluated for the operation and control of one COBAS AMPLICOR instrument and for two COBAS AMPLICOR instruments run simultaneously to perform and detect nucleic acid amplification reactions. A total of 3,384 results were analyzed. The initial accuracy of the results was 99.91%. Three errors of omission of transfer of data from the COBAS AMPLICOR to the AMPLILINK system were observed. Two of these errors were from a single specimen, where both the analyte and internal control results were not transmitted. These errors did not interfere with the correctness of any other data. There were no interruptions of runs, and no data were mixed. AMPLILINK increased convenience, saved labor, and was found to be a very useful addition for clinical laboratories performing molecular-diagnostic procedures with the COBAS AMPLICOR system.
Subject(s)
Polymerase Chain Reaction/methods , Software , Evaluation Studies as Topic , User-Computer InterfaceABSTRACT
We evaluated the COBAS AMPLICOR (CA) PCR system (Roche Diagnostic Systems) designed for automated PCR amplification and detection of nucleic acids from infectious agents in clinical samples. The Roche AMPLICOR microwell plate (MWP) PCR was the reference method. CA amplifies target nucleic acid, captures the biotinylated amplification products by using magnetic particles coated with specific oligonucleotide probes, and detects the bound products colorimetrically. For Mycobacterium tuberculosis, the correlation of the results of CA tests with those of MWP tests was 100% with 230 samples, including 20 culture-positive samples. For hepatitis C virus, the correlation was 100% with 214 samples, including 60 positive samples. MultiPlex CA analysis of 199 cervical specimens for Chlamydia trachomatis, Neisseria gonorrhoeae, and the internal control gave 100% concordance. These samples included 19 C. trachomatis and 3 N. gonorrhoeae culture-positive samples. Overall, the agreement between PCR methods for all 842 comparisons was 100%. Compared with culture, the sensitivities of the assays for C. trachomatis and M tuberculosis were > or = 95%. After spiking alternating amplification tubes in the CA system with 10(14) copies of the Chlamydia amplicon per ml, we were unable to demonstrate any carryover cross-contamination of negative samples. Using the criteria of the College of American Pathologists workload recording method, we found that the total hands-on time to produce CA PCR results was 4.4, 7.9, and 3.3 min for M. tuberculosis, hepatis C virus, and the MultiPlexed assay for chlamydia plus gonorrhea and an internal control, respectively. The CA system brings true PCR automation to laboratories. In addition to the accuracy of automated results, the CA system provides labor savings, provides containment of the amplification and detection components of PCR, and supports both MultiPlex amplification and sequential algorithm (ReFlex) detection of analytes.
Subject(s)
Bacteriological Techniques/instrumentation , Polymerase Chain Reaction/instrumentation , Virology/instrumentation , Automation , Bacteriological Techniques/statistics & numerical data , Chlamydia trachomatis/genetics , Chlamydia trachomatis/isolation & purification , Evaluation Studies as Topic , Female , Hepacivirus/genetics , Hepacivirus/isolation & purification , Humans , Laboratories/organization & administration , Mycobacterium tuberculosis/genetics , Mycobacterium tuberculosis/isolation & purification , Neisseria gonorrhoeae/genetics , Neisseria gonorrhoeae/isolation & purification , Polymerase Chain Reaction/methods , Polymerase Chain Reaction/statistics & numerical data , Sensitivity and Specificity , Virology/methods , Virology/statistics & numerical dataABSTRACT
The Abbott enzyme immunoassay (Abbott Laboratories, North Chicago, Ill.) for human T-cell lymphotropic virus type III (HTLV-III) antibody was evaluated to determine the effect of using heat-inactivated (56 degrees C for 30 min) serum as the sample. Each of 58 nonreactive serum samples gave a higher A492 value when tested after heat inactivation. Ten of the samples became reactive after heating. Heat-inactivated serum should not be used in the current Abbott HTLV-III antibody test, because this can cause false-positive results.
