QUANTITATIVE TEST FOR CMV BY RT-PCR

VIRUS DETECTION: Cytomegalovirus

INDICATIONS FOR ORDERING: Detection of CMV infection in new-borns and children up to 12 months, and in immunocompromised patients, especially post-transplant

METHOD USED: Real time quantitative polymerase chain reaction kits provided by Qiagen India for detection of CMV

SPECIMENS – Type, storage and transport
Type: Non-diluted peripheral blood sample in an EDTA (lavender) tube. PLEASE AVOID HEPARINATED SAMPLES.
Whole Blood: 3 mL
Transport: Specimens must be received within 48 hours of collection
Storage: Serum Plasma: Separate specimens must be submitted when multiple tests are ordered.
Extracted Viral nucleic acids: Separate specimens must be submitted when multiple tests are ordered.
Unacceptable samples: Specimens collected in anticoagulants other than EDTA, less or no plasma serum in the EDTA vial

TEST DESCRIPTION: This is a viral DNA based real-time quantitative test, based on the amplification of specific regions of the pathogen genome. The viral genome is isolated from the peripheral blood serum and employed in the real-time PCR for amplification. In this assay, the amplified product is detected via fluorescent dyes. Kit is provided with specific primers and probes that bind to the amplified product. The fluorescence intensities allow the detection and quantitation of the PCR product. The kit is provided with an internal control (IC) which is employed into the testing sample, positive and negative controls. For a negative sample, the Ct value should be >27 to validate the nucleic acids obtained are pure. A threshold value of 0.03 is set to quantitate the fluorescence. The result can be deduced using the standard curve into copies/ml of sample:
(Result (copies/μl)x Elution Volume (μl))/(Sample Volume (ml))
The linear range is set between 1.83 – 8 log copies/ml. If CMV DNA detected in this range, the infection is reported. Below the sensitivity range, the infection may not be reported.

ANALYTICAL SENSITIVITY: The assay detects the presence of CMV for the copies in dilution as low as 0.24 copies/µl (p = 0.05). This means that there is a 95% probability that 0.24 copies/μl will be detected, if present.

TURNAROUND TIME: Next day from the receipt of sample

QUALITY ASSURANCE & COMPETENCY TESTING: Regular internal quality checks and intra-lab comparisons are performed to ensure accurate and precise results. Highly trained personnel performing this test undergo regular competency assessments and attend regular conferences and educational programs in order to stay upbeat with the newer advances in the biology and diagnostics of the disease in question.

ACCREDIATION: NOT IN NABL SCOPE