SARS-CoV-2 Spike Protein Receptor Binding Domain (RBD) Nucleic Acid Test (Serum/Plasma)
This test detects genetic material from the SARS-CoV-2 virus, specifically the receptor-binding domain (RBD) of its spike protein, using a serum or plasma sample. It helps confirm whether you have been infected with the virus at some point.
["This test supports diagnosis of past COVID-19 infection by identifying viral genetic material."]
Key facts at a glance
- LOINC
- 98734-7
- Short code
- SARS-CoV-2 S RBD NAb SerPl IA-aCnc
- Synonyms
- SARS-CoV-2 S RBD NAb SerPl IA-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ia
- 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
What This Test Measures
The test looks for the genetic sequence of the RBD region of the SARS-CoV-2 virus spike protein. This part of the virus binds to human cells to enter them, making it a key target for detection. The presence of this genetic material indicates past infection, as the virus has been eliminated by your immune system but its genetic code remains detectable in your blood.
Why It’s Done
Doctors may order this test if you have had symptoms of COVID-19 (such as fever, cough, or fatigue) and want to confirm past infection, even if you tested negative with other types of tests. It can also be used in research or surveillance settings to track virus presence.
Sample Collection and Preparation
A blood sample is drawn from your arm, and the serum or plasma portion is separated for testing. This sample is sent to a lab where genetic material is extracted and analyzed for the RBD sequence.
What to Expect Before the Test
No special preparation is needed. You may eat and drink normally before the blood draw. If you’re on blood-thinning medication, inform your healthcare provider beforehand.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
SARS-CoV-2 RBD NA Test
Frequently asked questions
This test is primarily used to detect past infection rather than active illness. Unlike antigen or antibody tests, it identifies genetic material that may linger after the virus has been cleared. It’s particularly useful for research, vaccine studies, or identifying individuals who may have been exposed but remain asymptomatic.
How long does it take to get results?
Can this test be used to determine immunity?
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