Isolation of specific antigens from Angiostrongylus cantonensis. 1. Preparative flatbed isoelectric focusing.

Electrophoresis on SDS gel and analytical isoelectric focusing showed that a crude extract of Angiostrongylus cantonensis consisted of at least 40 protein components with molecular weights ranging from 13 000-70 000 and isoelectric points of pI values ranging from 3.7-10.0. Crossed-immunoelectrophoresis with a hyperimmune antiserum to A. cantonensis showed at least 40 different antigenic components in the crude worm extract which were cross-reactive with those of Ascaris suum, Metastrongylus apri and Toxocara canis. Using preparative isoelectric focusing, the somatic worm preparation was divided into 13 equal fractions, of which 3, 4 and 5, with pI values of 3.7, 4.0 and 4.45 respectively, were later shown by immunoelectrophoretic techniques and enzyme-linked immunosorbent assay to contain antigens specific to A. cantonensis.