Anti-Streptolysin O(ASO) Determination Reagent(Latex Immunoturbidimetry) is an in vitro diagnostic quantitative test kit. Streptolysin O (SLO) is a toxic and lethal, exocellular immunogenic protein produced and released in response to Group A Streptococcal pyogenes. The release of SLO stimulates the production of Anti-Streptolysin O (ASO) antibodies to neutralise the SLO’s haemolytic effects. The O in the name stands for oxygen-labile. The Anti-Streptolysin (ASO) test is used to determine recent streptococcal infection and post streptococcal complications which includes rheumatic fever and glomerulonephritis. The presence and level of ASO antibodies in human serum directly reflects the extent and degree of infection. Elevated levels of ASO may also be present in other conditions including scarlet fever, acute rheumatoid arthritis, tonsillitis and various other streptococcal infections as well as in health carriers.