Serum or plasma concentration of a substance measured by immunoassay (e.g., tetramethylbenzidine-based chemiluminescent immunoassay)

What This Test Measures

The test identifies a specific substance (e.g., a protein, hormone, or enzyme) in your serum or plasma. The method used is highly sensitive, often involving a chemical reaction that produces a measurable signal. This helps ensure accurate detection even at low concentrations.

Why It’s Done

Your healthcare provider may order this test to diagnose or monitor conditions related to the substance being measured. For example, it could help check for infections, autoimmune disorders, or other health issues tied to the presence or absence of this substance in your blood.

Common Uses

This test is often used in screening, confirmation, or monitoring scenarios where precise detection of trace amounts of a substance is critical. It may be part of a broader panel or used independently depending on clinical needs.

Sample Collection and Preparation

A blood sample is drawn from a vein, typically in your arm. The blood is then processed to separate serum or plasma, which is sent to the lab for testing. You may be asked to fast or avoid certain medications before the test, depending on the substance being measured.