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