ABSTRACT
Objective To determine the minimum detection limit of the novel coronavirus 2019-nCoV nucleic acid detection kit (fluorescent PCR method) developed and produced by Shanghai Jienuo Biotechnology Co., Ltd., and to verify whether it can effectively detect the novel coronavirus at the minimum detection limit level. Methods 20 different clinical positive samples were diluted to 5 concentration gradients of 62 500, 12 500, 2 500, 500, and 100 copies/mL, and the new coronavirus 2019-nCoV nucleic acid detection kit (fluorescent PCR method) was used for 3 repetitions Test, initially determine the minimum detection limit range;use 3 batches of kits to perform 20 repeated tests on 20 different clinical positive samples diluted to 5 concentration gradients of 1,500, 700, 500, 300, and 150 copies/mL, and further Determine the minimum detection limit;another 25 different clinical positive samples were diluted to the minimum detection limit level, and 20 repeated tests were performed with 3 consecutive batches of kits to verify the minimum detection limit. Results The positive detection rate of samples was 100% at the 4 concentration levels of 62 500, 12 500, 2 500, and 500 copies/mL. At the concentration level of 100 copies/mL, the positive detection rate of samples was =55%. The minimum detection limit is between 500 and 100 copies/mL;after 20 repeated determinations, the positive detection rate of the sample at the 3 concentration levels of 1, 500, 700, and 500 copies/mL is =95%, and the positive detection rate of the sample is =95%, and the positive detection rate of 300 and 150 copies/mL 2 The positive detection rate of the samples at each concentration level is less than 95%, and the minimum detection limit is determined to be 500 copies/mL;25 positive samples diluted to the minimum detection limit concentration level, the positive detection rate is more than 95%. Conclusion The minimum detection limit of the new coronavirus 2019-nCoV nucleic acid detection kit (fluorescent PCR method) developed and produced by Shanghai Genuo Biotechnology Co., Ltd. is determined to be 500 copies/mL. The sample can effectively detect viral nucleic acid and meets my country's relevant requirements for the minimum detection limit of detection reagents.