CHLOROACTIVATED LATEX-PARTICLES FOR COVALENT COUPLING OF ANTIBODIES -APPLICATION TO IMMUNOASSAYS

The aim of the present work is to prepare and characterize a functiona lized latex with chloromethyl groups on the surface and to perform the covalent coupling of anti-human serum albumin (a-HSA) IgG protein. Th e chloromethyl-styrene latex (CMS) was synthesized by means of a core- shell emulsion polymerization in a batch reactor. The monodisperse-obt ained latex was characterized by determining the diameter (TEM and PCS ), the surface charge density (conductometric and potentiometric titra tion), the amount of chloromethyl groups on the surface (hydrolysis re action), and the stability vs electrolyte concentration (turbidity mea surements). Electrokinetic characterization was also performed (electr ophoretic mobility Versus pH and ionic strength). Ige was chemically b ound to the latex particles under different sensitization and block-st abilization conditions. Colloidal stability of complexes was studied t o select an immunolatex suitable for the development of latex immunoas says. The final part of this work consists of a study of the immunorea ctivity of the IgG-latex complexes at different pH and ionic strength, in particular under physiological conditions. The results show that c hemically bound IgG to chloromethyl latex provides an IgG-latex comple x suitable for application in immunodiagnosis tests.