Test Catalog

Test ID: SCOVT    
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), RNA Detection, ddPCR, Tissue

Method Description Describes how the test is performed and provides a method-specific reference

The assay is a laboratory-developed modification of the Bio-Rad severe respiratory syndrome coronavirus 2 (SARS-CoV-2) droplet digital polymerase chain reaction (ddPCR) assay to generate results in formalin-fixed paraffin-embedded (FFPE) tissue specimens. RNA is extracted from either scraped unstained slides or tissue scrolls. The eluate is incorporated into the reaction mixture, followed by generation of individual reaction droplets by the QX200 Automated Droplet Generator. After completion of PCR, the droplets are analyzed for presence or absence of amplified viral target sequences using the QX200 Droplet Reader.


The PCR reaction mixture contains primers and probes for 2 target sequences within the SARS-CoV-2 nucleocapsid gene (N1 and N2) and a reference human ribonuclease P protein subunit 30-encoding gene (RPP30) sequence. Results are generated and reported as positive, negative, or indeterminate. The sensitivity of the assay is dependent on the timing of the specimen collection (in relation to symptom onset) and the quality, quantity, and type of specimen submitted. This test is not normalized to the size of the submitted tissue per section. The limit of detection varies based on the number of droplets generated but is approximately 5 copies of the viral genome.(Package insert: Bio-Rad SARS-CoV-2 ddPCR Test for use on the QX200 and QXDx Droplet Digital PCR Systems. Bio-Rad Laboratories, Inc; 04/2020)

PDF Report Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.


Report Available The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

7 to 10 days

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

Unused portions of blocks will be returned. Unused slides and/or scrolls are stored indefinitely.

Performing Laboratory Location Indicates the location of the laboratory that performs the test