Procalcitonin (PCT) is a protein that is a precursor hormone secreted by the C cells of the thyroid gland. The main role of PCT is to play a regulatory role in infection and inflammation. In healthy people, PCT levels are very low, but in infections and inflammatory responses, PCT levels can be significantly elevated.

The PCT antigen is a test for PCT levels, which can be used to diagnose infections and inflammatory responses. PCT antigen testing can help doctors determine the severity of infection and inflammation and guide the development of treatment options.

A PCT antibody is an antibody used to detect the PCT antigen. It can bind to the PCT antigen to form a complex that detects the presence of the PCT antigen. PCT antibodies can be used to study the role of PCT in infection and inflammatory responses, as well as the interaction of PCT with other proteins.