Latex agglutination slide test for the qualitative and semiquantitative determination of Anti-Streptolysin O (ASO) in human serum.The ASO reagent contains latex particles coated with streptolysin O antigen. When the reagent is mixed with serum containing ASO the particles will agglutinate. This is interpreted as a positive sample. Detection of ASO in serum may aid in the diagnosis of streptococcal infections. Infections promoted by acute streptococcal infection result in the production of anti-streptolysin O antibodies due to the presence of the streptolysin O antigen liberated by the bacteria. Information on the extent and degree of infection can be obtained from the measurement of serum ASO levels. Increased ASO levels are also associated with rheumatic fever and glomerulonephritis.