Clinical Virology Laboratory -
Specimen Collection Guidelines for CNAT (CMV) PCR Tests

Blood for the CMV PCR test must be collected in a yellow ACD tube (7-10 mL capacity) containing 5-7 mL of solution A or B to provide as many cells as possible for the assay. It is recommended that blood is shipped to the laboratory soon after being drawn for optimal results although blood less than 72 hours old is still acceptable. Performing this test on blood more than 72 hours old compromises the validity of the assay and may give false-negative results.

FK506 (Tacrolimus) blood samples which INCLUDE the TACROLIMUS TEST REQUISITION may be shipped with CMV PCR samples to the same address. They will be rerouted to the appropriate lab upon arrival in Virology. Do not send FK506 (Tacrolimus) blood samples to Virology without the Tacrolimus Test Requisition form.

Delivery Deadlines for Blood for the CNAT Test

The CMV PCR assay is performed daily from Monday-Saturday on blood that arrives before 9 AM. The strict cut-off time of 9 AM is due to the length of time required to process it, perform the assay and report the results. Blood older than 72 hours at the time of testing will be rejected.