Osteopontin Staining Method

**Semantic type:** Laboratory Procedure

**Definition:** An immunohistochemical procedure for identification of osteopontin, a highly phosphorylated, calcium binding sialoprotein. Elevation in osteopontin levels are seen during sepsis and metastatic cancers. It is used as a tumor marker.

**Synonyms:** - OPN Staining Method - SPP1 Staining Method