Optimization of urinary sample preparation process for real-time PCR detection of BK virus / 第二军医大学学报

ABSTRACT

Objective: To develop an effective preparation method to improve the sensitivity and accuracy of real-time PCR in detection of BK virus's (BKV's) load in urine samples. Methods: A total of 24 samples documented as positive probes in primary detection were enrolled in this study. The candidate samples were prepared by 4 different approaches: unprocessed urine, BKV's DNA extracted from urine, 1:10 diluted urine, and 1:100 diluted urine; and then they were subjected to real-time PCR examination to obtain the viral load. The data obtained were analyzed by SPSS 11.0. Results: The four different preparation processes for urinary specimens had significant impact on detection results of real-time PCR. Three samples were negative in the unprocessed urine group and 66.7% of its samples had the lowest viral loads compared with the other three groups. Two samples in the 1:100 diluted urine group were negative and 79.2% of its samples had the highest viral loads, but its median load was similar to that of the 1:10 group. Viral gene was detected in all samples in the DNA extraction group and 1:10 diluted urine group, but the loss of the target gene was more severe in the DNA extraction group. Conclusion: The 1:10 diluted urine is better for real-time PCR detection of BKV's load, as it lose less viral gene and is more efficient, easy to perform and economical.