Calprotectin is a neutrophil cytosolic protein with antimicrobial properties, which is present at increased concentrat ion in stool samples during bowel inflammation.

The stability of the protein to degradation keeps it stable in faeces for up to 7 days at room temperature, making it an ideal analyte.

Calprotectin is released by activation of leukocytes, giving increased levels in plasma, cerebral spinal fluid, synovial fluid, urine or stools as a consequence of disease in the relevant organ(s). Calprotectin inhibits zinc-dependent enzyme systems, as a result kills microbes and induces apoptosis in normal and cancer cells. In the presence of calcium, calprotectin is remarkably resistant to protelolytic degradation and so is stable in stools kept at room temperature for 7 days.