Serum/plasma mass concentration of a substance detected via immunoassay (e.g., a marker protein)

What This Test Measures

This test quantifies a particular protein or substance in your serum or plasma. The method used is an immunoassay, which detects and quantifies the presence of specific molecules in your blood. This can include markers for inflammation, infection, genetic conditions, or other physiological processes. The exact substance may vary based on clinical need, but it often relates to proteins like cytokines, enzymes, or antibodies.

Why It’s Done

Doctors may order this test to diagnose or monitor conditions such as autoimmune diseases, infections, kidney or liver function, or certain cancers. It can also help track responses to treatments like medications or therapies that affect protein levels.

Common Uses

Common reasons for this test include evaluating immune system function, detecting genetic disorders, assessing organ health, or identifying markers of chronic diseases. For example, it might be used to monitor protein levels in patients with kidney disease or to check for signs of inflammation.

What to Expect Before the Test

No special preparation is typically required, but you may be asked to fast for a few hours before the blood draw if the test involves fasting-related measurements. Avoid smoking or consuming certain medications for a specified time before the test, if instructed by your healthcare provider.