Ultrastructural localization of gold-labeled anti-IgM-antibodies and type A retrovirus particles in endoplasmic cisternae and vesicles of IgM-producing human B cell hybridomas.

Simultaneous appearance of IgM and type A retro-virus particles in endoplasmic cisternae and vesicles of human hybridomas has been demonstrated for the first time by immunogold-labeling at ultrastructural level. A suspected link between type A particle and IgM gene-expression in hybridoma cells could not be substantiated in this study.