Description_x000D_ Application_x000D_ Type IV collagen has been found to play a key role in angiogenesis, neurological diseases and metastasis. Collagen from human placenta has been used to assess the bioelectric effects of quinine on airway epithelial cells, to study the selective toxicity of engineered lentvirus lytic peptides and in a particle aggregation assay for the rapid detection of fibronectin, fibrinogen and collagen receptors on Staphylococcus aureus. It has also been used in a magnesium-dependent, collagen-binding assay during characterization of human lung tumor-associated antigens._x000D_ Biochem/physiol Actions_x000D_ During development, collagen IV is ubiquitously distributed in BMs. During the maturation process, this network gets partially replaced in a remarkably tissue specific manner, defining BM structure and function. Collagen IV has been shown to bind to platelets, hepatocytes, keratinocytes, endothelial, mesangial, pancreatic cells and some tumor cells._x000D_ Tissue injury in the autoimmune disease Goodpasture syndrome is due to pathogenic autoantibodies targeting the Collagen IV α3 chain . Mutations in COL4A5 are associated with Alport syndrome._x000D_ Components_x000D_ All collagen molecules are composed of three polypeptide chains arranged in a triple helical conformation, with a primary structure that is mostly a repeating motif with glycine in every third position and proline or 4-hydroxyproline frequently preceding the glycine residue. Type IV collagen occurs only in the basement membranes and contains up to six genetically distinct a-chains._x000D_ Caution_x000D_ Store this product at -20°C. It will retain activity for 2 years under these conditions._x000D_ Preparation Note_x000D_ This product is supplied as a solution in 0.5 M acetic acid. It can be used to coat tissue-culture surfaces to promote cell attachment. The amount used in these applications is dependent on the cell type, plastic ware and incubation time. A recommended amount is 0.5-5 μg/cm2. It was prepared by pepsin extraction and chromatographic purification._x000D_ Other Notes_x000D_ Collagen is classified into a number of structurally and genetically distinct types. We use the nomenclature proposed by Bornstein and Traub. Be wary of confusing Sigma-type designations with recognized collagen classification types.