A comparison of two procedures for labelling the surface of the hydatid disease organism, Echinococcus granulosus, with 125I.

Living, intact protoscoleces of the British horse and sheep strains of Echinococcus granulosus were subjected to surface radioiodination procedures using 125I and Iodogen and 125I-Bolton Hunter reagent. Subsequent combined electron microscopy and autoradiography revealed specific surface membrane labelling with the Iodogen procedure, but significant tegumental labelling with the Bolton-Hunter reagent. The two parasite strains yielded different profiles of electrophoretically separated labelled proteins; the Iodogen method, not surprisingly, resulted in a less complex pattern of labelled polypeptides than the Bolton and Hunter reagent.