Abstract
BACKGROUND: Cytomegalovirus (CMV) DNA viral load testing is routinely performed in centers that serve patients that are immunosuppressed from organ or hematopoietic stem cell transplantation. Clinical laboratories that offer this testing often face practical concerns about the storage of these specimens to ensure accurate measurement for patient care. The published studies that assess CMV DNA stability at 4°C have done so only up to 72 h. OBJECTIVE: Our objective was to determine the stability of CMV DNA in whole blood and plasma for clinical viral load testing over a 14 day period. STUDY DESIGN: Twenty-one plasma samples that were CMV-positive and twenty whole blood samples (including eleven CMV-negative whole blood samples spiked with CMV-positive plasma) were stored at 4°C and underwent extraction and amplification at 3 time points: Day 0, Day 7, and Day 14. RESULTS: Log(10) values were calculated and t-test was performed on the values comparing Day 0 to Day 14 for plasma and whole blood. There was no statistically significant difference between Day 0 and Day 14 for both specimen types, including the CMV-negative whole blood specimens that were spiked with CMV-positive plasma. CONCLUSIONS: CMV DNA in plasma and whole blood is stable for 14 days at a temperature of 4°C.