The substance of nucleic acid detection is the nucleic acid of virus. Nucleic acid detection is to determine whether the patient is infected by COVID-19 by detecting whether there is nucleic acid of foreign invasive virus in respiratory tract samples, blood or feces. Therefore, once the nucleic acid is "positive", it can prove that there is a virus in the patient.
After COVID-19 infects the human body, it will first reproduce in the respiratory system, so we can judge whether the human body is infected with the virus by detecting the virus nucleic acid in sputum and nasopharyngeal swab. Therefore, positive nucleic acid detection can be used as a new standard for the diagnosis of novel coronavirus infection.
Methods of nucleic acid detection in novel coronavirus;
For nucleic acid detection in novel coronavirus, samples were collected according to the "Sample Requirements" section of the kit instructions. Routine sample types include throat swab, nasal swab, sputum, bronchial lavage fluid, alveolar lavage fluid and so on.
After obtaining patient samples, it is necessary to test them as soon as possible. If the samples that need to be transported cannot be tested immediately, they shall be packaged at low temperature according to the requirements of the instructions and sent to a special testing institution for testing. After receiving the sample, the testing institution shall extract nucleic acid from the sample, and the nucleic acid extraction reagent shall use the nucleic acid extraction kit specified in the approved product specification.
Viral RNA needs to be reverse transcribed into cDNA before amplification and detection. PCR amplification and detection should use the fluorescent quantitative PCR instrument specified in the approved product manual. The Ct value of the sample obtained by fluorescence quantitative PCR can determine whether the patient sample contains novel coronavirus.