View information on our visitor policy. >>

Information about coming with a patient for their appointment, test or surgery. >>

Text size: a a a

Laboratory Medicine

Test catalogue

Anti-Streptolysin O Titre

Test Name

Anti-Streptolysin O Titre (ASOT, Streptozyme)

Gold Tube Specimen Type / Requirements

Container Type = 1 Gold Top

Minimum Volume = 3 mL Serum

Tubes must fill to at least ½ or greater of its vacuum capacity

Specimen Handling

Collection Instructions: Collect sample in gold or red top with or without gel separator. Write your initials, date and time of collection on the collection label.

Special Instructions Acute and convalescent sera (10-14 days after onset of illness) should be analyzed to document acute infection Separate from cells within 2 hours of collection. Store and send frozen.

Rejection Criteria: Plasma, Gross hemolysis, Unlabeled or Not Sufficient Quantity Samples.

Stability: Stable at room temperature for 8 hours, refrigerated for 48 Hrs and frozen at -20C or colder for 20 days. Thaw samples only once.

Transportation: Send sample to core lab as soon as possible.

Required Documentation

Turnaround Time (TAT)

5 Days

Test Utilization

Routine > 5 Days

Reference Value

Adults and Children >3 years

Negative: < 200 IU/mL

Children <=3 years

Negative: < 50 IUmL

A 4 fold rise or fall in antibody titre is compatible with a recent streptococcal infection. The peak ASOT is usually achieved by 3 to 5 weeks post infection, then declines over the next 6 to 8 weeks.

Test code



Latex Agglutination

Testing Location

Referred Out – ON, Canada (ROICL02)

Other Information