Preparation of fixed antigenic, non-oncogenic and protective neoplastic cells.

Transplantable spontaneous mammary adenocarcinoma and sarcoma P 1798 cells were incubated with vibrio cholera neuraminidase (VCN), then fixed cells demonstrated ability to exclude trypan blue dye and to immunized animals and produce cytotoxic sera of high titers. The fixed neuramindase-treated tumor cells became non-oncogenic and protected the host against high doses of fresh untreated homologous tumors.