Serum or plasma substance concentration (e.g., protein) by immunoassay

What This Test Measures

This test detects the presence and concentration of a particular protein or substance in your serum or plasma. The method involves using antibodies to bind specifically to the target analyte, allowing for highly sensitive detection. The result is expressed as a concentration value, often in milligrams per deciliter (mg/dL) or another relevant unit, depending on the analyte.

Why It’s Done

Healthcare providers may order this test to screen for, diagnose, or monitor conditions such as infections, inflammatory diseases, kidney function, or certain genetic disorders. It can also help assess protein loss in urine or other body fluids.

Common Uses

For example, this test might be used to check for abnormal protein levels in conditions like multiple myeloma (a cancer of plasma cells), acute-phase reactants in infections or inflammation, or specific carrier proteins in metabolic disorders.

How the Test Works

Blood is drawn and separated into serum or plasma. The sample is then analyzed using an immunoassay, which detects the target protein or substance by measuring its interaction with antibodies. The test is highly specific and sensitive, often automated for quick and accurate results.