The Biorex Diagnostics FOB- Transferrin Rapid Test Device is a one step chromatographic immunoassay for the qualitative determination of human hemoglobin (Hb) and human transferrin (Tf) in stool samples to detect gastrointestinal bleeding. The test is intended for use by health care professionals as an aid in the diagnosis of premature syndrome linked to the intestinal bleeding.

Colorectal cancer is a leading cause of illness and death in the Western world. Screening with fecal occult blood tests is based on the concept that important target colonic neoplasm, such as early-stage cancer and large adenomatous polyps, will bleed, for which may be detected by an occult blood test. When gastrointestinal blood is lost, the stool will contain a combination of intact or nearly intact hemoglobin, intact heme, and heme-derived porphyrins in amounts that depend on the site, the amount of bleeding and the transit time through the gut.