Also called: ASO titer, ASLO, Strep A antibody test
Report
{context.blood_test.parameters} Parameters
What it checks
Report delivery
Test for
Age group
Commonly advised for
Understanding The Antistreptolysin O (ASO) Titre
The Antistreptolysin O (ASO) Titre is a blood test used to detect a recent infection by Group A Streptococcus bacteria. Unlike a throat culture, which diagnoses an active strep throat infection while it is happening, the ASO Titre looks for the aftermath. It measures antibodies the body produces against "Streptolysin O," a toxic enzyme released by the bacteria. This test is primarily ordered when a patient presents with symptoms of complications that occur weeks after a strep infection—specifically Rheumatic Fever (which affects the heart and joints) or Post-Streptococcal Glomerulonephritis (a kidney disease). It is a vital tool for connecting current unexplained symptoms (like joint pain or kidney issues) to a past, perhaps untreated, strep infection.
Components Measured:
The test focuses on a specific immune marker:
Antistreptolysin O Antibodies: These are proteins created by the immune system to neutralize the toxins produced by Group A Strep bacteria.
Titre Level: The test measures the amount (titre) of these antibodies in the blood. A higher number indicates a stronger immune response, suggesting a recent or severe infection. The antibodies typically appear 1 to 3 weeks after the initial infection, peak around 3 to 5 weeks, and then gradually decline over months.
Preparation:
Preparation for an ASO Titre is simple and generally requires no special changes to your routine.
Fasting: Fasting is usually not required. You can eat and drink normally before the test.
Medications: Inform your doctor about any medications you are taking, particularly corticosteroids or antibiotics, as these can suppress the immune system and potentially lower antibody levels, leading to a false-negative result.
Recent Illness: Let the doctor know if you have had a sore throat or skin infection in the last few months, even if it seemed mild.
Procedure:
The test is a standard venous blood draw that takes only a few minutes:
A healthcare professional selects a vein, typically in the inner elbow.
The area is cleaned with an antiseptic to prevent infection.
An elastic band (tourniquet) is tied around the arm to swell the veins with blood.
A needle is inserted, and a small amount of blood is collected into a tube.
The needle is removed, and a cotton ball or bandage is applied to the site.
The sample is sent to a laboratory where it is tested for the reaction between your serum and the streptolysin antigen.
Risks:
The risks associated with an ASO Titre test are minimal:
Bruising: Minor bruising at the needle site is common but harmless.
Pain: A slight pinch during needle insertion and mild soreness afterward.
Infection: Extremely rare risk of infection at the puncture site.
Fainting: Some patients may feel lightheaded during the blood draw.
Normal Ranges:
Results are measured in International Units per milliliter (IU/mL). Reference ranges can vary slightly between laboratories, but general guidelines are:
Adults: A test is usually considered negative (normal) if the level is below 200 IU/mL.
Children (School-aged): Because children are exposed to strep bacteria more frequently, their "normal" baseline is higher. A level below 400 IU/mL is often considered normal for children (especially ages 5–15).
Infants/Toddlers: Levels are typically very low, similar to adults, as they have had less exposure.
Interpretation:
A doctor interprets ASO results in conjunction with physical symptoms. A single test result is often not enough to confirm a diagnosis; doctors look for patterns.
Negative (Low) Titre: Indicates you likely have not had a strep infection recently. However, if symptoms are strong, the doctor may repeat the test in 10 days to see if levels rise (seroconversion).
Elevated or Rising Titre: This is clinically significant.
Rheumatic Fever: High ASO combined with joint swelling, fever, or heart murmurs suggests Rheumatic Fever.
Glomerulonephritis: High ASO combined with blood in urine, swelling (edema), or high blood pressure suggests post-streptococcal kidney inflammation.
False Positives/Negatives: ASO levels might not rise if the infection was on the skin (impetigo) rather than the throat, or if antibiotics were taken early. Conversely, levels can remain elevated for months after an infection has cleared, so a high number doesn't always mean the disease is currently active—it just means it was there.
The ASO Titre checks for a past throat infection with a streptococcus germ. It is advised if:
Tapadia Diagnostic Centre in Dehradun offers NABL-accredited ASO Titre test from a Blood sample(s). ASO titer, ASLO, Strep A antibody test is also prescribed for Fever, joint pain, chest pain, swelling, shortness of breath. Established in 1989, this doctor-led diagnostic centre ensures high accuracy. Home sample collection and walk-in facility available at our Dehradun center. Pay at the centre with no advance payment. Book online or visit us.
ASO Titre in Dehradun
Rated 4.6 on Google
From 6,477 patient reviews across our Hyderabad centres.
Every report, kept for you
Past reports stay in your account and can be downloaded again.
NABL accredited
Every result reviewed by a qualified pathologist before it reaches you.
Four decades of practice
A family-run diagnostic centre, trusted by doctors and households since 1989


Master Health Checkup (Blood) in Dehradun
HIV 1 & 2 Antibodies, Serum-Elisa Method in Dehradun
Dengue IgG, IgM Antibodies + NS1 Antigen-Rapid, Serum in Dehradun
Lipoprotein A (Lp A), Serum in Dehradun
Erythrocyte Sedimentation Rate (ESR) in Dehradun
Thyroxine Total (T4), Serum in Dehradun
Triiodothyronine Total (T3), Serum in Dehradun
CA 19.9 (Pancreatic Cancer Marker), Serum in Dehradun
NIPT with Microdeletions in Dehradun
NIPT Basic in Dehradun
Complete Blood Picture (CBP) in Dehradun
Serum Phosphorus Test in Dehradun
TIBC in Dehradun
Urology Profile in Dehradun
Beta HCG Free, Serum (Pregnancy Test) in Dehradun
Viral Screening in Dehradun
AFP Test in Dehradun
Microalbuminuria test in Dehradun
Diabetes Testing (FBS + PLBS) in Dehradun
Antithrombin III in Dehradun
D-dimer test in Dehradun
Creatine Kinase (CK) Test in Dehradun
AST Test in Dehradun
Cardiac Markers in Dehradun
Pap Smear - LBC in Dehradun
DVT Profile in Dehradun
Bleeding Time and Clotting Time (BT & CT) in Dehradun
Estradiol Test in Dehradun
hs-CRP Test in Dehradun
Alkaline Phosphatase (ALP) Test in Dehradun
Fertility Profile in Dehradun
Albumin blood test in Dehradun
Troponin T in Dehradun
Infertility Profile Extended in Dehradun
Electrolyte Panel in Dehradun
Anticardiolipin Antibodies (IgG) in Dehradun
PSA Test in Dehradun
FSH Test in Dehradun
STD Panel in Dehradun
PCOS Profile in Dehradun
Serum Iron Test in Dehradun
Cardiac Profile-III in Dehradun
Plasma Fibrinogen Test in Dehradun
HBsAg Test in Dehradun
Cardiac Biomarker Test in Dehradun
Herpes Simplex Virus (HSV) Types 1 and 2 Antibody Test in Dehradun
Antenatal Profile in Dehradun
Activated Partial Thromboplastin Time in Dehradun
Lipid Panel in Dehradun
Fine Needle Aspiration Cytology in Dehradun
CRP test in Dehradun
Joint Pain / SLE / Collagen Profile-I in Dehradun
PAPP-A Test in Dehradun
Insulin Test in Dehradun
Triple Screen Test in Dehradun
Anti-HCV Test in Dehradun
Basic Metabolic Panel (BMP) in Dehradun
Very low-density lipoprotein (VLDL) test in Dehradun
Free Testosterone in Dehradun
Triglycerides Test in Dehradun
Quad Screen in Dehradun
Folic Acid in Dehradun
Urinalysis in Dehradun
CEA Test in Dehradun
Ferritin Test in Dehradun
Transferrin Saturation% in Dehradun
Protein C Antigen in Dehradun
Alpha Feto Protein (AFP) - Fluid in Dehradun
CPK (MB) Test in Dehradun
Lupus Anticoagulant Testing in Dehradun
Reticulocyte Count in Dehradun
Infertility Profile-Basic in Dehradun
Beta hCG Test in Dehradun
DIABETIC PROFILE in Dehradun
LH Test in Dehradun
Anti-Müllerian Hormone (AMH) Test in Dehradun
Bile Salts and Bile Pigments, Urine in Dehradun
HbA1c in Dehradun
Vitamin D (1,25-Dihydroxyvitamin D) in Dehradun
Liver Function Test (LFT) in Dehradun
Anemia Profile Basic in Dehradun
Rheumatoid Factor in Dehradun
Widal Test in Dehradun
Bilirubin blood test in Dehradun
Inhibin A, Tumor Marker, Serum in Dehradun
Thyroid Function Tests in Dehradun
eGFR in Dehradun
Menopause Profile in Dehradun
EXTENDED DIABETIC PROFILE in Dehradun
LDH Test in Dehradun
Total Cholesterol Test in Dehradun
Random Blood Sugar Test in Dehradun
Total Protein Test in Dehradun
RPR test in Dehradun
Anti-dsDNA Test in Dehradun
HDL Cholesterol in Dehradun
Blood Type Test in Dehradun
ASO Titre in Dehradun
Blood Urea(Serum) Test in Dehradun
Postprandial Blood Sugar Test in Dehradun
Back Pain Profile in Dehradun
ANA test in Dehradun
Serum Creatinine Test in Dehradun
PT/INR Test in Dehradun
Fasting Blood Sugar Test in Dehradun
Extended Anemia Profile III Executive in Dehradun
Kidney Function Test (Renal Profile) in Dehradun
Serum Magnesium Test in Dehradun
Well-woman exam in Dehradun
LDL cholesterol test in Dehradun
Prolactin Test in Dehradun
Malaria Blood Smear in Dehradun
Liver Function Test (+GGT) in Dehradun
TPHA Test in Dehradun
Hepatitis B Surface Antigen (HBsAg) Test in Dehradun
Antenatal Profile 2 in Dehradun
TSH Test in Dehradun
Cardiac Catheterization in Dehradun
Cardiolipin Antibody (IgM) in Dehradun
Master Health Checkup (BL+RADIO) in Dehradun
Calcium Profile in Dehradun
Coagulation Profile in Dehradun
Uric Acid Test in Dehradun
Vitamin D (25 - Hydroxy Vitamin D, Serum) in Dehradun
Globulin Test in Dehradun
Fever Profile Test in Dehradun
Connective Tissue Disease Profile in Dehradun
Calcium Blood Test in Dehradun
IHC in Dehradun
Estriol Unconjugated (E3) Test in Dehradun
Blood Typing in Dehradun
Vitamin B12 Test in Dehradun
Serum Cortisol in Dehradun
Double Marker Test in Dehradun
Pap Smear, Conventional in Dehradun
Protein S Activity in Dehradun
Non-Invasive Prenatal Testing (NIPT) in Dehradun
whole exome sequencing in Dehradun
Newborn Screening (NBS) in Dehradun
Apolipoprotein A1 (Apo A1), Serum in Dehradun
Apolipoprotein B (Apo B), Serum in Dehradun
Renal Function Test (RFT) in Dehradun