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 Gwalior 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 Gwalior center. Pay at the centre with no advance payment. Book online or visit us.
ASO Titre in Gwalior
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 Gwalior
HIV 1 & 2 Antibodies, Serum-Elisa Method in Gwalior
Dengue IgG, IgM Antibodies + NS1 Antigen-Rapid, Serum in Gwalior
Lipoprotein A (Lp A), Serum in Gwalior
Erythrocyte Sedimentation Rate (ESR) in Gwalior
Thyroxine Total (T4), Serum in Gwalior
Triiodothyronine Total (T3), Serum in Gwalior
CA 19.9 (Pancreatic Cancer Marker), Serum in Gwalior
NIPT with Microdeletions in Gwalior
NIPT Basic in Gwalior
Complete Blood Picture (CBP) in Gwalior
Serum Phosphorus Test in Gwalior
TIBC in Gwalior
Urology Profile in Gwalior
Beta HCG Free, Serum (Pregnancy Test) in Gwalior
Viral Screening in Gwalior
AFP Test in Gwalior
Microalbuminuria test in Gwalior
Diabetes Testing (FBS + PLBS) in Gwalior
Antithrombin III in Gwalior
D-dimer test in Gwalior
Creatine Kinase (CK) Test in Gwalior
AST Test in Gwalior
Cardiac Markers in Gwalior
Pap Smear - LBC in Gwalior
DVT Profile in Gwalior
Bleeding Time and Clotting Time (BT & CT) in Gwalior
Estradiol Test in Gwalior
hs-CRP Test in Gwalior
Alkaline Phosphatase (ALP) Test in Gwalior
Fertility Profile in Gwalior
Albumin blood test in Gwalior
Troponin T in Gwalior
Infertility Profile Extended in Gwalior
Electrolyte Panel in Gwalior
Anticardiolipin Antibodies (IgG) in Gwalior
PSA Test in Gwalior
FSH Test in Gwalior
STD Panel in Gwalior
PCOS Profile in Gwalior
Serum Iron Test in Gwalior
Cardiac Profile-III in Gwalior
Plasma Fibrinogen Test in Gwalior
HBsAg Test in Gwalior
Cardiac Biomarker Test in Gwalior
Herpes Simplex Virus (HSV) Types 1 and 2 Antibody Test in Gwalior
Antenatal Profile in Gwalior
Activated Partial Thromboplastin Time in Gwalior
Lipid Panel in Gwalior
Fine Needle Aspiration Cytology in Gwalior
CRP test in Gwalior
Joint Pain / SLE / Collagen Profile-I in Gwalior
PAPP-A Test in Gwalior
Insulin Test in Gwalior
Triple Screen Test in Gwalior
Anti-HCV Test in Gwalior
Basic Metabolic Panel (BMP) in Gwalior
Very low-density lipoprotein (VLDL) test in Gwalior
Free Testosterone in Gwalior
Triglycerides Test in Gwalior
Quad Screen in Gwalior
Folic Acid in Gwalior
Urinalysis in Gwalior
CEA Test in Gwalior
Ferritin Test in Gwalior
Transferrin Saturation% in Gwalior
Protein C Antigen in Gwalior
Alpha Feto Protein (AFP) - Fluid in Gwalior
CPK (MB) Test in Gwalior
Lupus Anticoagulant Testing in Gwalior
Reticulocyte Count in Gwalior
Infertility Profile-Basic in Gwalior
Beta hCG Test in Gwalior
DIABETIC PROFILE in Gwalior
LH Test in Gwalior
Anti-Müllerian Hormone (AMH) Test in Gwalior
Bile Salts and Bile Pigments, Urine in Gwalior
HbA1c in Gwalior
Vitamin D (1,25-Dihydroxyvitamin D) in Gwalior
Liver Function Test (LFT) in Gwalior
Anemia Profile Basic in Gwalior
Rheumatoid Factor in Gwalior
Widal Test in Gwalior
Bilirubin blood test in Gwalior
Inhibin A, Tumor Marker, Serum in Gwalior
Thyroid Function Tests in Gwalior
eGFR in Gwalior
Menopause Profile in Gwalior
EXTENDED DIABETIC PROFILE in Gwalior
LDH Test in Gwalior
Total Cholesterol Test in Gwalior
Random Blood Sugar Test in Gwalior
Total Protein Test in Gwalior
RPR test in Gwalior
Anti-dsDNA Test in Gwalior
HDL Cholesterol in Gwalior
Blood Type Test in Gwalior
ASO Titre in Gwalior
Blood Urea(Serum) Test in Gwalior
Postprandial Blood Sugar Test in Gwalior
Back Pain Profile in Gwalior
ANA test in Gwalior
Serum Creatinine Test in Gwalior
PT/INR Test in Gwalior
Fasting Blood Sugar Test in Gwalior
Extended Anemia Profile III Executive in Gwalior
Kidney Function Test (Renal Profile) in Gwalior
Serum Magnesium Test in Gwalior
Well-woman exam in Gwalior
LDL cholesterol test in Gwalior
Prolactin Test in Gwalior
Malaria Blood Smear in Gwalior
Liver Function Test (+GGT) in Gwalior
TPHA Test in Gwalior
Hepatitis B Surface Antigen (HBsAg) Test in Gwalior
Antenatal Profile 2 in Gwalior
TSH Test in Gwalior
Cardiac Catheterization in Gwalior
Cardiolipin Antibody (IgM) in Gwalior
Master Health Checkup (BL+RADIO) in Gwalior
Calcium Profile in Gwalior
Coagulation Profile in Gwalior
Uric Acid Test in Gwalior
Vitamin D (25 - Hydroxy Vitamin D, Serum) in Gwalior
Globulin Test in Gwalior
Fever Profile Test in Gwalior
Connective Tissue Disease Profile in Gwalior
Calcium Blood Test in Gwalior
IHC in Gwalior
Estriol Unconjugated (E3) Test in Gwalior
Blood Typing in Gwalior
Vitamin B12 Test in Gwalior
Serum Cortisol in Gwalior
Double Marker Test in Gwalior
Pap Smear, Conventional in Gwalior
Protein S Activity in Gwalior
Non-Invasive Prenatal Testing (NIPT) in Gwalior
whole exome sequencing in Gwalior
Newborn Screening (NBS) in Gwalior
Apolipoprotein A1 (Apo A1), Serum in Gwalior
Apolipoprotein B (Apo B), Serum in Gwalior
Renal Function Test (RFT) in Gwalior