DiaSorin Molecular Simplex RT-PCR
The DiaSorin Molecular Simplexa™ COVID-19 Direct assay system is a real-time RT-PCR system that enables the direct amplification of Coronavirus SARS-CoV-2 RNA from LRT specimens from patients suspected of COVID-19 by their health care provider.
Michigan Medicine has independently validated this test for use for the following alternate specimens only: tracheal aspirates, endotracheal aspirates and bronchoalveolar lavage fluid. Oropharyngeal swabs can be tested but have not been independently validated for this assay by Michigan Medicine and results will include language attesting to this.
Results are for the identification of SARS-CoV-2 RNA. SARS-CoV-2 RNA is generally detectable in LRT specimens during the acute phase of infection.
The Simplexa™ COVID-19 Direct assay is intended for use by qualified and trained clinical laboratory personnel specifically instructed and trained in the techniques of real-time PCR and in vitro diagnostic procedures. Simplexa™ COVID-19 Direct is only for use under the Food and Drug Administration’s Emergency Use Authorization.
Positive results are indicative of the presence of SARS-CoV-2 RNA; clinical correlation with patient history and other diagnostic information is necessary to determine patient infection status. Positive results do not rule out bacterial infection or co-infection with other viruses. Laboratories within the United States and its territories are required to report all positive results to the appropriate public health authorities.
Negative results do not preclude SARS-CoV-2 infection and should not be used as the sole basis for patient management decisions. Negative results must be combined with clinical observations, patient history, and epidemiological information. False-negative results may occur if the viruses are present at a level that is below the analytical sensitivity of the assay or if the virus has genomic mutations, insertions, deletions, or rearrangements or if performed very early in the course of illness.
Invalid results indicate the inability to conclusively determine presence or absence of SARS-CoV2 RNA in the patient sample. This result may be due to 1) Internal Control (IC) failure, or 2) failure to detect sufficient specimen volume
Optimum specimen types and timing for peak viral levels during infections caused by SARS-CoV-2 have not been determined. Collection of multiple specimens from the same patient may be necessary to detect the virus. The possibility of a false negative result should especially be considered if the patient’s recent exposures or clinical presentation suggest that SARS-CoV-2 infection is possible and diagnostic tests for other causes of illness (e.g., other respiratory illness) are negative. If SARS-CoV-2 infection is still suspected, re-testing should be considered in consultation with public health authorities.
The test will be performed multiple times per day with results reported within 12 to 18 hours of receipt of specimen in the laboratory contingent upon testing capacity.
Bronchoalveolar lavage(BAL), tracheal aspirate or Endotracheal aspirate.
Collect 2-3 mL into a sterile, leak-proof, screw-cap sputum collection cup or sterile dry container.
Oropharyngeal swab: Insert swab into the posterior pharynx and tonsillar areas. Rub swab over both tonsillar pillars and posterior oropharynx and avoid touching the tongue, teeth, and gums.
Laboratories within the United States and its territories are required to report all positive results to the appropriate public health authorities.
Additional information from the CDC can be found below:
Additional information about the interpretation and use of this test can be found at:
Simplexa™ COVID-19 Direct – FDA www.fda.gov › media › download
Assay lower limit of detection: 500 copies/mL (0.5 copies/µL)
The DiaSorin Molecular Simplexa™ COVID-19 Direct assay system is a real-time RT-PCR system that enables the direct amplification of Coronavirus SARS-CoV-2 RNA from nasopharyngeal swabs (NPS). The system consists of the Simplexa™ COVID-19 Direct assay, the LIAISON® MDX (with LIAISON® MDX Studio Software), the Direct Amplification Disc and associated accessories. In the Simplexa™ COVID-19 Direct assay, fluorescent probes are used together with corresponding forward and reverse primers to amplify SARS-CoV-2 viral RNA and internal control RNA. The assay targets two different regions of the SARS-CoV-2 genome, ORF1ab and S gene. The S gene encodes the spike glycoprotein of the SARS-CoV-2 (COVID-19 virus) and is also targeted to specifically detect the presence of SARS-CoV-2. The ORF1ab region encodes well-conserved non-structural proteins and therefore is less susceptible to recombination.