Test: Real-Time DNA PCR on Cell-Free Sample (DNA PCR)
- Qualitative Detection in Plasma for HHV-6A and HHV-6B
Due to the ubiquitous nature of human herpesviruses HHV-6, HHV-7, the use of traditional whole blood PCR methods to detect DNA in blood cells or tissue has limited value. When performed on whole blood samples, these PCR tests may detect DNA from a latent viral infection rather than an active infection associated with disease complications. In contrast, detection of high concentrations of viral DNA in cell-free samples such as plasma and cerebrospinal fluid (CSF) suggests the presence of virions or viral DNA from degenerating infected cells. Detection of herpesvirus DNA in cell-free samples is an important indicator of active tissue or central nervous system (CNS) infection.
DNA present in the cell-free sample is extracted using a commercial kit. To amplify the small amounts of relevant viral DNA present, viral “gene of interest” specific primers and probes, deoxyribonucleotides, and a thermo-stable DNA polymerase are added to the PCR reaction.
Volume / Collection Type
Whole blood to be processed to plasma by Coppe Laboratories6 – 10 mL collected in ACD tube3 mLLess than 48 hours from collection to arrival in lab, room temperatureRoom temperature
Alternate Plasma: Whole blood sample collected in ACD and processed to plasma1 mL0.5 mLRefrigerator 6 days; frozen 1 yearIf frozen, send on dry ice. If refrigerated, send with ice packs
Specimen:Whole blood to be processed to plasma by Coppe LaboratoriesVolume / Collection Type:6 – 10 mL collected in ACD tubeMinimum:3 mLStorage:Less than 48 hours from collection to arrival in lab, room temperatureShipping:Room temperatureSpecimen:Alternate Plasma: Whole blood sample collected in ACD and processed to plasmaVolume / Collection Type:1 mLMinimum:0.5 mLStorage:Refrigerator 6 days; frozen 1 yearShipping:If frozen, send on dry ice. If refrigerated, send with ice packs
Causes for Rejection
- Specimens submitted in the improper tube or container
- Specimens not accompanied by a requisition or incomplete requisition
- Unlabeled specimens
- Leaking containers
- Insufficient quantity of specimen
- Improper storage
- Failure to receive samples prior to expiration
Turn Around Time
Results available within five business days of specimen receipt in the lab.
Quantitative Results for Plasma Samples
Report as Detected / Not Detected