Eating gum and then taking a throat swab for nucleic acid testing may affect the accuracy of the throat swab test; taking a nasal swab for nucleic acid testing has no effect. Pharyngeal swabs are used to collect secretions from deep within the pharynx for testing. Eating gum secretes a lot of saliva, which dilutes the secretions from the respiratory tract to reduce the density of the virus. If a pharyngeal swab is done, when the viral density in the specimen taken is below a certain level, a situation of experimental error may occur, affecting the accuracy of the pharyngeal swab test. Nasal swabs are taken with a cotton swab to collect secretions from the nasal cavity for testing, and having chewing gum before having a nucleic acid test does not affect the accuracy of the nasal swab test. It is recommended that people have detailed knowledge before doing the nucleic acid test to avoid any experimental errors.