Test Overview
Test Methodology

Agglutination of sensitized sheep cells

Test Usage

Aid in the diagnosis of current or previous group A streptococcal infections. Screening for antibodies to streptococcal antigens NADase, DNAase, streptokinase (ASK), streptolysin O (ASO) and hyaluronidase (AH): Positive test titered to 1:800; endpoint beyond 1:800 reported as > 1:800.

Reference Range *

< 1:100

Test Limitations

The value of a single determination is limited. Sequential determinations may give the trend in antibody production and allow clinical conclusions with regard to the progress of the disease and treatment. False negatives may be found in patients with decreased immune response. Since there is a 30% false negative Streptozyme incidence in sera which have only a slight elevation of a single antibody titer, the Streptozyme test could miss a borderline streptococcal antibody titer. Test Sensitivity: < 1:100.

Test Details
Days Set Up
Monday - Friday
Analytic Time

8 hours

Soft Order Code
MiChart Code
Streptomycin Level
  • ADNAase
  • AH
  • AH (Anti-Hyaluronidase)
  • ANADase
  • ASK
  • ASK (Anti-Streptokinase)
  • ASO (Anti-Streptolysin O)
  • DNAase Antibodies
  • Hyaluronidase Antibodies
  • NADase Antibodies
  • Strep-O
  • Streptococcal Antibodies
  • Streptokinase Antibodies
  • Streptolysin O Antibody
  • Streptozyme Screen
Chemical Pathology
Specimen Requirements
Collection Instructions


Alternate Specimen
Red top tube; plasma
Normal Volume
0.5 mL serum
Minimum Volume
0.3 mL serum
Additional Information

Antibodies to streptococcal A exoenzymes may develop in rheumatic fever, glomerulonephritis, bacterial endocarditis, scarlet fever, and other related conditions. The most conclusive data is an increase in titer on successive specimens taken several days apart. Antibodies increase 1-3 weeks after onset and decrease 8-10 weeks after uncomplicated infection. Approximately 80% of Streptozyme positive sera have an ASO of 166 IU or above while an additional 10% showed an ASK or AH also above 166 IU. The remaining 10% agglutination may be due to antibodies to other streptococcal exoenzymes or to the combined effect of several antibodies which individually would fall below 166 IU. The accuracy of the test in patients with streptococcals infection is 95% and correlates well in patients with streptococcal pyoderma and poststreptococcal kidney involvement.

CPT Code
Fee Code
NY State Approved