When cystic fluid of Taenia solium metacestodes (CF) was filtrated through Sephacryl S-300 Superfine, major proteins were in fractions III and IV. Major protein in fraction III was Band C protein of 150 kDa and that in fraction IV was Band N protein (Choi et al., 1990). When CF was electrophoresed in 0.9% agarose gel and reacted with anti-CF rabbit serum (RACF), two main bands, a long outer and a short inner band, were precipitated, together with 8 minor bands. RACF reacted with fraction III forming the long outer band whereas RACF formed the short inner band with fraction IV in immunoelectrophoresis (IEP). The long outer precipitin band of CF fraction III was similar to antigen B in hydatid fluid (HF) of Oriol et al. (1971), while the short inner band of CF fraction IV was similar to HF antigen 5 of Capron et al. (1967). When HF was reacted with RACF, the short inner band was immunoprecipitated without forming the long outer band. Common antigenicity between CF and HF seemed to exist in fraction IV rather than in fraction III of CF. Patient sera of neurocysticercosis reacted more frequently with fraction III than with fraction IV.
