This test card is used for quantitative determination of procalcitonin (PCT) in human serum, plasma or whole blood in vitro. Procalcitonin (PCT) is a hormone composed of 116 amino acids with a molecular weight of about 12.7kd. PCT is expressed by neuroendocrine cells (including C cells in thyroid, lung and pancreas tissues) and is cleaved to calcitonin, carboxy terminal peptide and amino terminal peptide. There is only a small amount of PCT in the blood of healthy people. PCT increased significantly after bacterial infection. Animal model test showed that PCT could be expressed in many tissues when sepsis occurred. The increase of PCT was found in bacterial sepsis, especially in severe sepsis and septic shock. PCT can be used as a prognostic indicator of sepsis, but also a reliable indicator of severe acute pancreatitis and its major complications. PCT can be used as an indicator of antibiotic selection and efficacy judgment for patients with community acquired respiratory tract infection and air conditioning induced pneumonia.