回顾性检测和分析本实验室在新冠肺炎流行早期快速筛查检测新型冠状病毒(SARS-CoV-2)核酸结果，总结检测失败经验供临床实验室参考。

首先对50例咽拭子样本，分别用本实验室所用试剂A和亳州市疾控中心提供的试剂B进行实时荧光定量PCR(quantitative real-time PCR)平行双盲检测，以评估本实验室用试剂A的可靠性。后续使用试剂A进行常规检测，发现37 250例样本中有1 354例检测结果异常，其中1 286例为检测扩增失败样本，68例为检测信号曲线出现末尾起跳但是没有完整扩增的可疑样本。对检测结果异常的1 354例样本用试剂A进行复查，并对两次检测结果进行统计和分析。

采用A和B两种试剂分别检测50例已知结果样本的结果符合率为96.0% (48/50)，表明试剂A具有可靠性。用试剂A复检1 286例扩增失败样本，发现1 114例(86.63%)为阴性，25例(1.94%)单基因信号(15例ORF 1ab信号，10例N基因信号)曲线出现末尾起跳但是没有完整扩增，147例再次核酸制备/检测失败(11.43%)。在68例检测信号曲线出现末尾起跳但是没有完整扩增的可疑样本中，用试剂A复检57例单基因曲线末尾起跳样本，结果符合率为94.7%(54/57)，其检出病毒阳性率为10.53% (6/57)；复检另外11例双基因信号曲线出现末尾起跳但是没有完整扩增样本(可疑)，结果符合率为100% (11/11)，其中检出病毒阳性率为81.82% (9/11)。

荧光RT-PCR试剂盒A符合早期快速筛查病毒的实验室要求。检测时任何单基因或者双基因检测信号出现异常的末尾起跳时，必须进行重复检测才能保证结果的可靠和不漏检。同时，规范化的实验室操作和质量控制是保证操作精度和检测结果可重复的重要因素。

To improve the performance of nucleic acid amplification assay (RT-PCR)and obtain high quality screening results of SARS-CoV-2 detection through retrospective study of the data generated from confirmatory test.

RT-PCR kit A from our laboratory and the kit B provided by Bozhou Center for Disease Control and Prevention (CDC) were both utilized to analyze fifty throat swabs specimen in a double blind experimental manner. In the follow-up routine detection with reagent A, 1 354 of the 37 250 samples were found to have abnormal test results, among which 1 286 were failed test amplification samples, and 68 were abnormal test results of suspicious samples with end jump but no complete amplification. 1 354 samples were reexamined with reagent A, and the results of the two tests were statistically analyzed.

The coincidence rate of 50 samples with known results was 96.0% (48/50), indicating the reliability of reagent A. The results of 1 286 throat swabs specimen with failed amplification retested with the same A kits showed that there are 1 114 specimen of negative results, 15 specimens of abnormal ORF 1ab gene signal, 10 specimen of abnormal N gene signal, and 147 specimens were remained failure of detection with no data. The re-tested result from 57 specimens with abnormal single gene signal at the first test by using kit A showed high consistence with 94.70% coincidence rate and with 10.53% (6/57) positive rate. The re-tested results from analyzing 11 specimens with double abnormal genes signal at the first test by kit A also showed complete consistence results (100% coincidence rate) with 81.82% positive rate (9/11).

The Kit A meets laboratory requirements for rapid early screening of viruses. Meanwhile,the specimen with any abnormal detective signal during the RT-PCR reaction should be retested to ensure reliable results. At the same time, the precise operating in laboratory with a high quality of specimen are the most important criteria for obtaining the high quality data.