The principle of COVID-19 nucleic acid detection is mainly based on the fact that each organism's nucleic acid is different and has a specific nucleic acid sequence and DNA sequence. The virus is very small and can't be seen under ordinary optical microscope. However, as long as the COVID-19 gene sequence is detected in human body and amplified by fluorescence quantitative PCR, it can be detected according to the unique gene sequence of each virus. If the patient is infected with the virus, the fluorescence signal will be enhanced, so that a positive result can be displayed. If it is a patient sample without virus in nucleic acid detection, because there is no amplification of the target gene, the fluorescence signal enhancement can not be detected, and such a result belongs to COVID-19 negative nucleic acid detection.
In nucleic acid detection, we must pay more attention to personal diet, preferably a light diet, eat more fresh fruits and vegetables, try not to eat for two hours before detection, ensure adequate sleep, and avoid smoking and drinking, so as not to affect the detection results.