Nucleic acid generally refers to nucleic acid testing, there is generally no need to avoid food before doing nucleic acid testing, and the food itself will not affect the results. Nucleic acid test is generally check the respiratory tract, blood, fecal specimens, the test is the nucleic acid sequence of the pathogen, generally does not appear in the food, so the food itself will not affect the test results, do not need to pay too much attention to diet before the test. Before doing nucleic acid should ask the doctor about various contraindications, patients should first let the doctor to determine whether they suffer from rhinitis, pharyngitis and other diseases, to prevent nucleic acid test aggravate the symptoms of local discomfort. Try to relax and take a deep breath when doing the nucleic acid test. If you have suffered from blood diseases, throat diseases, taking anticoagulants and other risk factors, you need to inform the medical staff in advance, and consult the doctor in time when abnormalities occur, so as not to cause discomfort.