Effects of storage time on Cytomegalovirus DNA stability in plasma determined by quantitative real-time PCR

Quantitative real-time PCR (QRT-PCR) assays are faster, more precise, and more sensitive quantitative laboratory methods for monitoring serial CMV DNA viral load in patients undergoing organ or hematopoietic stem cell transplantation. Clinical laboratories often face practical concerns about the storage of specimens from these patients to ensure the accuracy and reproducibility of CMV viral load test results. Different studies that have assessed CMV DNA stability have shown mixed results. Therefore, we analyzed CMV DNA stability of 30 EDTA plasma samples in samples containing between 300 and 100,000copies/ml over a 21 day period. The concentration of CMV DNA in all samples stored at 4°C for 21 days did not differ significantly from the baseline viral load (t=0.242, p=0.810), and no trend was evident to indicate continued degradation over a 2 week period.