Method Description

The cobas cytomegalovirus (CMV) assay is a US Food and Drug Administration-approved, in vitro nucleic acid amplification test for the quantification of CMV DNA in human EDTA-plasma using the cobas 6800 System or cobas 8800 System for fully automated viral nucleic acid extraction (generic silica-based capture technique) and automated amplification and detection of the viral nucleic acid sequence. This polymerase chain reaction (PCR) assay amplifies sequences within CMV DNA polymerase (UL54) gene region and generates amplification products that are detected and quantified in real-time with 2 sequence-specific TaqMan probes. A non-CMV armored DNA quantitation standard (DNA-QS) is introduced into each specimen during sample preparation to serve as internal control for nucleic acid extraction and PCR amplification and detection processes. Fluorescent reporter dye-labeled TaqMan probes hybridized to the complementary CMV target sequences and DNA-QS sequence undergo hydrolysis during PCR amplification step to generate fluorescent signal detected in 2 different dye channels. Concentration of the CMV DNA in a patient's plasma sample is determined by a ratio of the intensity of the fluorescent dye from the cleaved CMV target sequence probes and that from the DNA-QS target probe detected throughout the PCR process.(Package insert: cobas CMV-Quantitative nucleic acid test for use on the cobas 6800/8800 Systems. Roche Molecular Systems, Inc; Rev 2.0, 12/2020)