[Preparation of nuclei from human placenta].

The authors describe a method of isolation and purification of nuclei from human placenta. The use of an homogenization containing divalent cations, an homogeneization method using a stepwise procedure, allow us to obtain nuclei free of cytoplasmic contaminants. Electronic microscopy shows that the material has kept morphological aspects of the nuclei of fresh tissue and these nuclei have kept an transcriptional activity.