A monoclonal antibody marker of human primitive endoderm.

Monoclonal antibodies were raised against the human germ-cell tumor line, LICR LON HT39/7. The cells of this human embryonal carcinoma cell line were first fixed in formol saline and then dehydrated prior to immunization so that antibodies were produced which reacted with antigens surviving conventional histological processing. Eleven hybrid clones secreted antibody that reacted with both formol saline-fixed and living cells of the immunogen. One of these antibodies, LICR LON FC 10.2, has been found to react with a membrane glycoprotein of molecular weight 200,000 restricted in distribution to the surfaces of undifferentiated teratoma-derived cell lines, the luminal surface of human fetal intestine and bronchus and areas of putative endodermal differentiation within germ-cell neoplasms.