Antigen Antibody Reaction in Serum (e.g., Immunoassay for Specific Antibody Detection)
This test measures the presence or level of specific antibodies in your blood serum, often used to detect infections, immune responses, or autoimmune conditions.
["Detects antibodies that may indicate past or current infections or immune activity."]
Key facts at a glance
- LOINC
- 5051-8
- Short code
- ASPNAB
- Synonyms
- A niger Ab Ser-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top serum tube or serum separator tube (SST)
- Units
- N/A
- Ref low
- 0.35
- Ref high
- 0.7
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Enzyme Immunoassay (EIA)
- CPT
- 86003
- SNOMED
- 395140008
- Specimen volume
- 1 mL serum
- Stability
- Stable for 7 days at 2-8°C; for longer storage, freeze at -20°C or below.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 hours
- Order
- routine
What This Test Measures
This test identifies antibodies—proteins produced by your immune system in response to exposure to specific substances, such as bacteria, viruses, or toxins. The method used may involve detecting these antibodies directly or through their interaction with a known antigen (e.g., via immunoassay techniques).
Common Uses
Such tests are commonly used to diagnose infections (e.g., HIV, hepatitis), evaluate immune function, screen for autoimmune diseases (e.g., lupus, rheumatoid arthritis), or confirm exposure to certain pathogens.
How the Test Works
Blood is drawn and processed to separate serum (the liquid part containing antibodies). The sample is then analyzed using a method like immunoassay, which detects the presence or concentration of specific antibodies bound to a target antigen.
Preparation for the Test
No special preparation is usually needed, but you may be asked to avoid certain medications or foods that could interfere with results. Always follow your healthcare provider’s instructions.
Reference range
Negative: <0.35 units/mL; Equivocal: 0.35-0.70 units/mL; Positive: >0.70 units/mL. Reference values may vary by laboratory and assay methodology.N/A
No special patient preparation required. Specimen collection can be performed at any time of day.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Positive results may indicate an active infection, immune response, or autoimmune activity. Negative results could mean no current exposure or infection, but further testing may be needed for confirmation. Results should always be interpreted by a healthcare professional in the context of your medical history and symptoms.
Short name
Antibody Test (Serum)
Frequently asked questions
Why might my doctor order this test?
What does a positive result mean?
Can lifestyle or diet affect this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy