IMMUNO-GOLD-LABELING OF CUT-1, CUT-2 AND CUTICLIN EPITOPES IN CAENORHABDITIS-ELEGANS AND HETERORHABDITIS SP PROCESSED BY HIGH-PRESSURE FREEZING AND FREEZE-SUBSTITUTION

CUT-1 and CUT-2 are two distinct protein components of cuticlin, the i nsoluble residue of the cuticles of nematodes. In previous experiments of gold-immuno-labelling on sections of chemically fixed Caenorbabdit is elegans, CUT-1 and CUT-2 epitopes were specifically lost. Cryo-immo bilization of C. elegans under high pressure followed by freeze-substi tution, however, resulted in a good preservation of these antigenic si tes and of the ultrastructure of the worms. The entomopathogenic nemat ode Heterorhabditis sp. processed by the same cryopreparation protocol has shown a strong reactivity with anti-sera raised against CUT-1, CU T-2 and against the whole cuticlin residue of C. elegans. The localiza tion of these epitopes was conserved across the two species.