Procalcitonin is a precursor of the peptide hormone called calcitonin. Procalcitonin is mainly produced by the C cells of the thyroid and certain endocrine cells of the lung. Under normal expression conditions, procalcitonin is immediately cleaved into three specific fragments, an N terminal residue, calcitonin and katacalcin. Levels of unprocessed procalcitonin have been shown to rise significantly after bacterial infection, trauma or shock. Recombinant Procalcitonin is a nonglycosylated Protein, containing 116 amino acids, with a molecular weight of 12.8 kDa.