Procalcitonin (PCT) Determination Reagent is an in vitro diagnostic quantitative test kit. PCT is a hormone-active protein, mainly synthesized in the thyroid follicular cells. It is composed of three parts of N-terminal residue-calcitonin-C terminal calcitonin. It is a precursor peptide of calcitonin and an inflammatory medium with a molecular weight of 13KD. It has become a new microbiological indicator for identifying serious bacterial infections in recent years. The level of serum PCT will increase when the patient is under severe bacteria, parasites, fungal infections, sepsis or MODS. So it can be used as adjunctive diagnosis of diseases such as bacterial infections.