Principle: Using loop-mediated isothermal amplification technology (LAMP), specific primers are designed for the nucleocapsid protein N gene and ORF1 ab gene of the new coronavirus (2019-nCoV). The reaction system contains the new coronavirus (2019-nCoV) For nucleic acids, the amplification of exponential amplification and combined with the fluorescent signal, real-time detection of the fluorescent signal during the amplification process using a fluorescent PCR instrument, to achieve the qualitative analysis of the novel coronavirus nucleic acid in the sample.
Quality control standards: The Ct value of the positive quality control should be < 15 and a specific amplification curve appears, and the negative quality control should have no Ct value and no specific amplification curve, and the test results are valid; otherwise, the test should be repeated.
Test result judgment
Positive: The test sample has a Ct value ? 25 and a specific amplification curve appears, which is judged as positive;
Negative: The tested sample has no Ct value and is judged as negative;
Suspect: test sample 25 <Ct value ?30 again detected value curves and specific amplification occurs, the penalty for the suspect sample, the sample should be re-extracted after this.
Detection time: 30 minutes
Test samples: whole blood, plasma, serum, throat swabs
Advantages: short detection time, high sensitivity and strong specificity
Disadvantages: low temperature transportation, high requirements for experimental conditions.
Reagent composition: buffer, DNA polymerase, reverse transcriptase, sealant, positive control, negative control.
Minimum detection volume: 1000 copies / ml.
Specificity: with human coronavirus HCoV-OC43 , human coronavirus HCoV-HKU1 , human coronavirus HCoV-229E , human coronavirus HCoV-NL63 , adenovirus, respiratory syncytial virus type A , human parainfluenza type 2 virus, human parainfluenza 3 virus , H1N1 subtype of influenza virus, the H5N1 subtype of influenza A virus, H7N9 subtype of influenza A virus, H9N2 subtype of influenza virus, Mycoplasmapneumonia, influenza B viruses are nothing more than specific amplification. Precision: Two cases of high- and low-concentration positive control were repeated 10 times, and their Ct value was CV?5%.