LIGAND-BINDING ASSAYS IN THE RESEARCH LABORATORY

The use of recombinant DNA technology in conjunction with traditional immunologic assays has made possible the significant advances that hav e occurred in the last decade in our understanding of cellular mechani sms at the molecular level. Many strategies of investigating the cellu lar mechanisms related to health and disease center around the identif ication, characterization, and regulation of the expression of protein s. Ligand assays, both antibody- and DNA/RNA hybridization-based, are powerful yet flexible tools used to pursue five basic lines of investi gation: 1) in vivo structure-function analysis at the cell or organism level; 2) isolation and sequence determination of the appropriate gen e, with subsequent expression of the gene either in vitro or in vivo; 3) manipulation of the protein's gene sequence and production of varia nts for functional analysis; 4) localization of the expression of a pa rticular gene within cells and tissues by in situ hybridization; and 5 ) elucidation of the regulatory points of the protein's expression.