Immunological studies on ovine fetuin: radioimmunoassay and comparison with related antigens

A radioimmunoassay for fetuin is described. It uses 125I]fetuin and rabbit antisera. The bound antigens are precipitated by anti-rabbit globulins coupled to Sepharose. This assay has been used to compare the immunological properties of ovine and bovine fetuin. It allows to detect a serum antigen cross-reacting with fetuin in pig species. A very faint reaction is observed with human fetal serum, that does not support the existence of a fetuin like antigen in human.