Antistreptolysin O (ASO)
Definition Antistreptolysin O (ASO) titer is a blood test to measure antibodies against streptolysin O, a substance produced by group A streptococcus bacteria. Antibodies are proteins our bodies produce when they detect harmful substances, such as bacteria. Alternative Names ASO titer; ASLO How the Test is Performed A blood sample is needed. How to Prepare for the Test DO NOT eat for 6 hours before the test. How the Test will Feel When the needle is inserted to draw blood, you may feel moderate pain, or only a prick. After the test, you ma...