Abstract
Monoclonal antibodies against mouse blastocysts in the adhesion stage of implantation were obtained by intrasplenic immunization with blastocysts either injected into the spleen after irradiation or transferred after drying on a piece of nitrocellulose paper. About 10 blastocysts were deposited at each of 4 immunizations before the spleen cells were used for hybridoma production. The supernatants obtained were examined for anti-blastocyst antibodies in indirect immunofluorescence labelling of native blastocysts and with ABC-immunoperoxidase staining either of blastocysts attached to nitrocellulose paper or of methanol-fixed blastocysts. Further, sections of paraffin-embedded blastocysts were used for detection of antigens.