Tetramethylbenzidine (TMB) substrate concentration in serum (immunoassay-based)

What Is TMB Used For?

TMB is primarily used as a substrate in immunoassays, which are lab tests that detect tiny amounts of substances in your blood. These tests often measure antibodies or proteins that could indicate infections, autoimmune conditions, or other health issues. Your doctor may order this test as part of a broader diagnostic process, such as screening for certain diseases or monitoring treatment responses.

How Is This Test Performed?

A blood sample is drawn from a vein, usually in your arm. The sample is processed to separate serum (the liquid part after clotting). The TMB substrate is then added to react with specific markers in the serum during the immunoassay process. The reaction produces a measurable signal, which is analyzed to determine the concentration of the target analyte.

Why Might Your Doctor Order This Test?

Your doctor may request this test if they suspect an immune-related condition, such as an infection, autoimmune disorder, or other health concern where antibody or protein levels are relevant. It could also be part of routine monitoring for conditions like cancer, inflammation, or organ function. Always discuss the reason for the test with your healthcare provider.

What Are Common Uses?

While TMB itself isn’t a standalone diagnostic test, it is a critical component in assays for detecting or quantifying substances like antibodies (e.g., for HIV, hepatitis, or other infections), certain proteins (e.g., tumor markers), or enzymes involved in disease processes. It’s often used in conjunction with other tests for accuracy.