Serum or Plasma Substance Concentration (Bromocresol Green Dye Binding)

What This Test Measures

The BCG dye binding test works by adding a specific dye (bromocresol green) to a sample of your blood. Healthy proteins in the blood bind to the dye, changing its color. The degree of color change is measured to estimate the concentration of certain proteins, particularly albumin, which is produced by the liver. This process indirectly reflects liver function and protein synthesis capacity.

Why It’s Done

Doctors may order this test to diagnose or monitor conditions affecting the liver, such as cirrhosis, liver disease, or malnutrition. It can also help assess how well the liver is producing essential proteins needed for overall health.

Common Uses and Conditions

This test is sometimes used alongside other liver function tests to provide a broader picture of liver health. It may also be part of routine evaluations for patients with chronic liver disease, kidney disease, or those undergoing treatment for conditions affecting protein metabolism.

What to Expect Before the Test

No special preparation is usually needed for this test. You may be asked to fast for a few hours before the blood draw, but this is not always required. Your doctor will provide specific instructions if applicable.