BKV Real-Time Quantitative PCR. The BKV standard was serially diluted prior to being assayed by real-time quantitative PCR. A. Raw amplification curves from precision study with primers BKV_5.1(r) and BKV_4.2(f). Input BKV DNA was 10 μl at concentrations of 106 copies/μl, 105 copies/μl, 104 copies/μl, 103 copies/μl, 102 copies/μl, 10 copies/μl and <10 copies/μl. B. Standard curve. Results of the regression were: slope -3.484, y-intercept 39.05 and efficiency 1.936. Similar results were obtained with other primer combinations.