ATOMIC-ABSORPTION SPECTROMETRIC DETECTION OF BIOTIN-CYMANTRENE AS A METALLO-TRACER FOR THE AVIDIN-BIOTIN SYSTEM

Biotin-cyclopentadienylmanganese tricarbonyl (biotin-cymantrene; bioti n-Cy) is proposed as a universal metallo-tracer for immunoassays. Asso ciated with the possibility of detecting this type of label (organomet allic moieties) along with different analytical procedures, this reage nt appears to be a universal system with the advantages of being inexp ensive, stable and directly detected (no substrate is required). The o ptimum conditions for detecting the organometallic label biotin-Cy wit h a Zeeman atomic absorption spectrometer and the affinity of biotin-C y for the streptavidin ligand immobilized on the walls of microtitre p lates, wells or tubes are described. The results obtained demonstrate the possibility of assaying a wide range of clinical parameters becaus e the detection limit of biotin-Cy is about 1 pg per assay. Based on t he competition between immobilized bovine serum albumin adsorbed on th e wall and free bovine serum albumin for specific polyclonal antibodie s, the streptavidin-metallo-biotin system was tested on a competitive immunoassay model and a satisfactory calibration graph was obtained.