Antistreptolysin-O Titer

Test/Profile Name

Antistreptolysin-O Titer

Test/Profile Code


Clinical Usefullness

This test measures the amount of ASO in the blood. The ASO test is used to determine if a strep infection with group A Streptococcus is the cause of glomerulonephritis kidney disease or rheumatic fever

Synonyms (Also knowns as)


Antistreptolysin-O (ASO) Titer

ASO (Antistreptolysin-O) Titer

DNA Streptococcal Antibody


Streptococcal Antibodies, Serum

Specimen Type and Minimal Volume

Serum 0.3 mL
Serum: Plain tube (Red)
SST tube (Yellow)


Not required

Test Equipment

Siemens, Dimension RXL Max

Test Method


Reference Range

For Adults 0-200 IU/ml
For Pediatric Less Than 150 IU/mL

Include Test


Reporting Time (Turn Around Time; TAT)

8 hrs

Clinical Information

A number of bacterial antigens have been identified in cultures of group A Streptococci. These extracellular products are primarily enzymatic proteins and include streptolysin O, streptokinase, hyaluronidase, deoxyribonucleases (DNases A, B, C, and D), and nicotinamide adenine nucleotidase. Antistreptolysin O (ASO) is an antibody targeted against streptolysin O, a toxic enzyme produced by group. A Streptococcus bacteria. ASO and anti-DNase B are the most common of several antibodies that are produced by the body's immune system in response to a strep infection with group A Streptococcus. A positive test can indicate recent or current group A, C, and G streptococcal infection (eg, upper airway infections, scarlet fever, toxic shock syndrome) and may support the diagnosis of post-streptococcal infection complication (eg, glomerulonephritis and rheumatic fever).

Related Disease/Condition

Scarlet fever
Rheumatic fever
Post Infectious Glomerulonephritis

Related Test

Antistreptolysin O titer