The agglutination test is a method of human serological examination, also known as the antigen-antibody reaction test. It uses the principle that antigen and antibody will react to check whether the serum contains specific antigens and specific antibodies. It is mainly used in the clinical examination of various pathogenesis, such as the examination of various bacterial infections, the examination of various viral infections, etc. The agglutination test is widely used in clinical practice. For example, in clinical practice, if a patient is examined for Streptococcus haemolyticus infection, the most common agglutination test is the anti-O test. If the anti-O concentration is abnormally high, it indicates that the body is infected with Streptococcus haemolyticus. By the same token, if the body is checked for S. typhi and S. paratyphi infection, it can be checked by the Fester’s reaction and the exophthalmia reaction. In addition for many viruses examination can also be done by agglutination test, such as hepatitis B virus, hepatitis C virus, AIDS virus, etc. can be examined by agglutination test.