For radioisotopic assays, the backgrounds are typically of 10-100 counts/min. BioFocusInc. is developing a system which features exceptional background reduction and about a thousand fold increase in detection sensitivity of the labeled molecules, e.g. antibodies to endogenous opioid peptides, peptide precursors and processing enzymes. With the MPD (Multi Gamma Photon Detector) background counts are reduced to a few counts per day, by only recording events compatible with a coincident 'triple gamma' signature of the iodine isotope utilized as a label. Members of the triple gamma family have half-lives ranging from minutes to days. As atoms they have diverse chemistries and can be incorporated into diverse molecules through standard chemistries. The halogen isotopes are also readily adduced to performed macro-molecules, such as the antigens and antibodies utilized in radioimmunoassays (RIA). These system characteristics confer the following advantages. * The quantity of isotope is reduced, because the background count is virtually eliminated. * There is a corresponding reduction in isotope purchase and radioisotope disposal costs. * Minute traces of biological molecules can be quantitated at much lower concentrate.Awardee's statement of the potential commercial applications of the research:The total market for in vitro diagnostic is about half a billion dollars/year; we estimate that the MPD-immunoassay will account for 5100/o of the immunoassay tests by 1995.National Institute on Drug Abuse (NIDA)
