Serum Bromocresol Green Protein Binding Capacity (BCG Protein Binding)
This test measures how well certain proteins in your blood bind to a dye called bromocresol green. It helps assess liver function and protein synthesis.
["Your liver’s ability to produce and manage proteins may be checked with this simple blood test."]
Key facts at a glance
- LOINC
- 30387-5
- Short code
- RBC # Gast
- Synonyms
- RBC # Gast
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- 2 N/A – 7 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84484
- SNOMED
- 302774002
- 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 Does This Test Measure?
The test evaluates protein binding capacity using bromocresol green, a dye that binds to specific proteins in serum. When the dye binds, it changes color, which is detected to estimate protein levels indirectly. This method helps assess liver function by reflecting how well proteins are synthesized and transported in the bloodstream.
Why Might You Need This Test?
Doctors may order this test if you have symptoms like fatigue, swelling, or unexplained weight loss that could indicate liver disease, malnutrition, or other conditions affecting protein metabolism.
Common Conditions Monitored
This test is sometimes used to monitor conditions such as chronic liver disease, cirrhosis, or protein-losing syndromes, though it’s not a direct measure of protein levels. It can complement other tests like albumin or liver enzymes.
Sample Collection and Preparation
A blood sample is drawn from a vein, typically in your arm. The serum (liquid part of blood after clotting) is separated and tested for dye binding. No special preparation is needed, but fasting may be advised in some cases depending on your doctor’s instructions.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
BCG Protein Binding Test
Frequently asked questions
This test indirectly reflects liver function by assessing protein binding capacity. Low results may suggest liver disease, malnutrition, or conditions impairing protein synthesis, but it’s not a standalone diagnostic tool. Results are often compared to baseline or other liver function tests for context.
A low result may indicate reduced protein production or binding capacity, which can be linked to liver dysfunction, severe malnutrition, or chronic inflammation. A high result is less commonly reported and may require further investigation to rule out technical errors or less typical causes.
Results are typically available within 1 to 3 business days, depending on lab processing times. Your healthcare provider will discuss them with you during your follow-up visit.
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 17, 2026. · Read our editorial policy