Detection of beta2-microglobulin in sera from diverse vertebrate species by the use of a heterologous radioimmunoassay.

The strong cross-reaction between rabbit and human beta2-microglobulins, as detected by goat antisera, has permitted the development of heterologous radioimmunoassays to detect homologues of beta2-microglobulin (beta2mu) in the sera of various vertebrate species. The assay based on the inhibition of the binding reaction between goat anti-rabbit beta2 mu and human beta2 mu divided the sera examined into two groups, one giving high levels of inhibition (approximately 80%). and the other lower levels (approximately 20%). There was no evident correlation between this division and phylogenetic classification. When the same group of sera was tested using the assay based on the inhibition of binding of rabbit beta2 mu to goat anti-human beta2 mu, a wide range of maximal levels of inhibition was observed, with clustering of phylogenetically related species.