STREPTOLYSIN O ANTIBODIES (ASO)
1 SST/1.0 mL serum (0.5 mL minimum). Centrifuge and refrigerate serum.
Refrigerate: 8 days; Frozen: 2 weeks
Document exposure to streptococcal streptolysin O. A marked rise in titer or a persistently elevated titer indicates that a Streptococcus infection or poststreptococcal sequelae are present. Concentrations of ASO antibodies are increased in 80-85% of patients with acute rheumatic fever.