Аннотация:The literature data on the regularities of the manifestation of tumorigenic capacity in somatic hybrids, on the correlation of this sign with the features of the in vitro transformation of hybrid cells, on the chromosomal stability and taking capacity of hybridomas have been analyzed. The expediency of the inoculation of animals with hybridomas, made considerably earlier than required by the traditional scheme of obtaining monoclonal antibodies, with a view to the selection of tumorigenic hybridoma variants is suggested. The aims of the experimental work have been determined.