Antibody
Detection of ASO via antistreptolysin-O titer or anti-deoxyribonuclease B (anti-DNase B) is a common way of testing for a group A streptococcal infection. These tests indicate if streptolysin antibodies are present. These proteins are only synthesized by lymphocytes in the event that streptolysin enters the immune system, thus this is a useful way of determining if a patient has the infection.