Method Description

The GeneXpert Dx System automates and integrates sample purification, nucleic acid amplification, and detection of the target sequence in simple or complex samples using real-time polymerase chain reaction (PCR). The system uses single-use disposable cartridges that hold the PCR reagents and host the PCR process. Because the cartridges are self-contained, cross-contamination between samples is minimized.

The Cepheid Xpert SA Nasal Complete Assay performed in the GeneXpert System is a qualitative in vitro diagnostic test designed for rapid detection of Staphylococcus aureus and methicillin-resistant S aureus (MRSA) from nasal swabs in patients at risk for nasal colonization. The test utilizes automated PCR for qualitative detection of proprietary sequences for the staphylococcal protein A (spa) gene, the gene for methicillin resistance (mecA), and the staphylococcal MRSA/SA S aureus DNA cassette chromosome mec (SCCmec) inserted into the S aureus chromosomal attB site. The assay includes a sample processing control to ensure the sample was processed correctly and to monitor for the presence of inhibitors in the PCR reaction. A probe check control verifies reagent rehydration, PCR tube filling in the cartridge, probe integrity, and dye stability.(Package insert: Xpert SA Nasal Complete 300-8799. Cepheid; Rev H, 09/2019)