Latex of immunodiagnosis for detecting the Chagas disease: II. Chemical coupling of antigen Ag36 onto carboxylated latexes

VERÓNICA D.G GONZALEZ; LUIS M. GUGLIOTTA; CARLA EUGENIA GIACOMELLI; GREGORIO R. MEIRA

Journal Material Science: Material in Medicine

Springer Sci.

Lugar: New York; Año: 2008 vol. 19 p. 789 - 795

0957-4530

A novel immunodiagnosis reagent for detecting the Chagas Disease was developed, by chemical coupling of antigen Ag36 of Trypanosoma cruzi onto two (carboxylated and core-shell) latexes. The coupling reactions involved the use of a carbodiimide intermediate. Bovine serum albumin (BSA) was used as a model protein for determining the appropriate conditions for its physical and chemical coupling. BSA showed an increased adsorption onto the base carboxylated latexes, with respect to a PS latex without carboxyl groups. The chemical bonding experiments only involved the carboxylated latexes. With BSA, the final density of covalently bound protein was 2.30 mg/m2. In addition, around 55% of the total linked protein was chemically coupled, and the reaction was little affected by the pH. With Ag36, the final density of covalently bound protein was 2.44 mg/m2, around 80% of the total linked protein was chemically coupled, and the chemical coupling was maximum at pH = 5 (i.e., close to the isoelectric point).