COMPARISON BETWEEN TWO DIFFERENT POTENTIOMETRIC METHODS FOR HUMAN ANTI-IMMUNOGLOBULIN G AND HUMAN IMMUNOGLOBULIN G

摘要

In this research we determined HIgG using anti-HIgG linked with urease directly in solution after an immunoprecipitation process able to concentrate HIgG up to 10,000-fold. In this method the immunocomplex was separated from excess HIgG and detected in solution by a gas diffusion potentiometric electrode for NH3 determination. Pre-treatment involving immunoprecipitation is performed with the aim of improving the sensitivity of a previous method able to determine anti-HIgG using a classic immunosensor. The incubation and the formation of an antigen-antibody complex are the first steps of the assay; then immunoprecipitation was obtained by adding protein G-agarose and removing non-specific binding protein by microcolumn. In this study we assume some modifications with the aim of determining lower concentrations of HIgG down to 0.60 μg l~(-1).