Metaphase chromosome preparation from cultured peripheral blood cells.

Chromosome preparations currently provide the only direct view of the genome as a whole. Although molecular methods allow a more detailed analysis of specific regions of the genome, the study of genetics is not complete without an appreciation of the metaphase cell. The stimulated T cell system described in this unit is the most widely used means of obtaining large numbers of mitotic cells for genetic analyses. Synchronization of the cell cycle in culture is described, combined with direct inhibition of chromosome condensation, to yield longer high-resolution prophase or prometaphase preparations. Such preparations are used for detailed analysis of microdeletions or subtle rearrangements, fine breakpoint analysis, and refined mapping. Microscope slide preparation of mitotic chromosomes from harvested cell culture suspensions is also explained in the support protocol.