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Hemoglobin Variant Surface Antigen (or Hemoglobin Variant Screening by Immunoassay)

Published: August 9, 2026Updated: August 16, 2026

This test checks for unusual or rare forms of hemoglobin, the protein in red blood cells that carries oxygen. Certain variants can cause health problems, including anemia or blood disorders.

Quick summary

["Identifying hemoglobin variants helps diagnose inherited blood conditions early."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
7905-3
Short code
HBV surface Ag SerPl Ql Nt
Synonyms
HBV surface Ag SerPl Ql Nt
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
0
Ref high
5
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
neut
CPT
82378
SNOMED
394995008
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your doctor may recommend this test if you have symptoms like fatigue, pale skin, unusual bruising, or a family history of blood disorders. It’s also used in newborn screening or before certain medical procedures.

How the Test Works

A small blood sample is drawn, and the lab uses an immunoassay method to detect specific hemoglobin variants. This method detects differences in the hemoglobin structure that standard tests might miss.

Sample Collection

Blood is collected from a vein in your arm, usually by a healthcare professional. The sample is sent to a lab for testing.

What to Expect Before the Test

No special preparation is needed, but inform your doctor about any medications or recent illnesses. Avoid strenuous activity before the draw if advised.

Reference range

Non-smokers: <2.5 ng/mL; Smokers: <5.0 ng/mLN/A

Specimen: serum

No special preparation required. For PSA, avoid sexual activity for 24-48 hours before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Detecting hemoglobin variants can help diagnose conditions like sickle cell disease, thalassemia, or other inherited blood disorders. Early detection may allow for better management and treatment options.

Short name

Hemoglobin Variant Screening

Frequently asked questions

What does a positive result mean?
A positive result indicates the presence of an unusual hemoglobin variant. Your doctor will discuss the findings with you and may recommend further testing or monitoring based on your symptoms and family history.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on lab processing times. Your healthcare provider will contact you with the results.
Can I fast before this test?
No fasting is required for this test, as it involves blood and does not rely on dietary factors.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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