[Competitive immunochemical determination of antigens using conjugates containing Co(II) and Ni(II)]. / Konkurentnoe immunokhimicheskoe opredelenie antigenov s pomoshch'iu kon"iugatov, soderzhashchikh iony Co(II) i Ni(II).

A new variant of competitive heterogeneous immunoassay for certain proteinaceous antigens has been developed. The assay is based on the use of the target protein conjugated with Co(II) or Ni(II) ions and immobilized Abs. The effect of catalytic hydrogen release allows quantitation of the metal ion labels by voltammetry at the final step of the assay. The conjugates have been characterized by spectrophotometry, voltammetry, atomic adsorption spectrometry, and nuclear magnetic relaxation. Based on the use of the conjugate RNase-diethylenetriaminepentaacetic acid-Co(II) (10:4:4), a competitive immunoassay for RNase has been developed, detecting the target protein in the range 2 x 10(-2)-2 x 10(-4) mg/ml.

[Noncompetitive immunochemical determination of ribonuclease using transition metal ions and the effect of catalytic hydrogen release]. / Nekonkurentnoe immunokhimicheskoe opredelenie ribonukleazy s ispol'zovaniem ionov perekhodnykh metallov i éffekta kataliticheskogo vydeleniia vodoroda.

A noncompetitive variant of immunochemical ribonuclease (RNase) determination has been developed, involving the use of Co(II) as a label. A variety of approaches to labeling the immunological reagent with the metal have been assessed. In the variant proposed, catalytic hydrogen release was used as a means of detecting the label, the amount of which was proportional to RNase concentration. Conditions making it possible to record catalytic hydrogen release fluxes were determined. In the presence of RNase, the electrocatalytic effect was maximum at a concentration of Co(II) in the ammoniac buffer, equal to 2 x 10(-4) M (pH 10.0). The dependence was linear in the range 4-2000 ng/ml RNase concentrations (threshold concentration, 2 ng/ml).