Abstract: The present invention relates to the discovery of a new protein complex in human biological materials that can be used for diagnostic and other purposes. The invention further relates to products, methods and uses related to said protein complex.

Abstract: The present invention provides a process for the extraction of proteins from gastrointestinal tract samples taken from humans or other mammals wherein the sample is mixed with an excess amount of aqueous extraction medium comprising at least one dissociating, disaggregating and/or chelating agent, homogenised in a closed vessel, the solid and liquid materials of the dispersion are separated from each other and the clear liquid extract is recovered.

Abstract: This study describes method for extraction and quantification of calprotectin (L1 protein) in feces by enzyme immunoassay. This protein is a prominent antimicrobial component of neutrophils, monocytes, macrophages and squamous epithelia. Calprotectin was stable in feces during storage for seven days at room temperature. Fecal calprotectin quantitated in a five gram sample taken from a 24 hours feces collection gave a reliable estimate of calprotectin found in the pooled collection. The assay had a within assay precision (=CV) of 1,9% and a between assay precision of 14,8%. The following mean fecal calprotectin levels were found: Healthy subjects (n=33) 3095 .mu.g/l, hospital controls (n=40): 14697 .mu.g/l, patients with inflammatory bowel disease (Crohn's disease and ulcerative colitis), (n=28) 40850 .mu.g/l. The differences between the means are highly significant.

Abstract: The invention concerns the two pure human granulocyte L1 proteins of pI 6.3 and pI 6.5, and mixtures thereof, methods for their isolation and purification, their use as marker proteins and antigenics, antisera produced against these proteins, methods for producing said antisera, the use of said antisera for the qualitative and quantitative determinatoin of L1 proteins, and test kits comprising said antisera.