Fluorescent Antibody Studies in vitro on Ascaris suum Goeze, 1782

Abstract

The immunology of Ascaris suum was studied in vitro using the fluorescent antibody technique. Fluorescein isothiocyanate labelling of globulin was used in the direct and indirect method and by a combination of both methods.Fluorescein labelled antibody was incorporated into precipitates at the mouth, excretory pore, anus and on the cuticle of third stage larvae.The possible intercuticular localization of fluorescent antibody in moulting larvae and fluorescence of the ends of broken larvae were further observed.Circumlarval precipitates did not form nor did the larvae fluoresce in normal serum.The results indicate (1) that antigenic sites are located at the natural orifices and cuticle and (2) that the dead internal tissues and possibly the moulting substance are also antigenic.