Fluorescent staining of nuclear envelope coated with heparin.

Naturally and artificially devitalized cells of various origin can be loaded with heparin and subsequently stained with DAPI, a newer fluorochrome (4',6-diamidino-2-phenylindole), leading to a bright yellow fluorescence of the nuclear envelope. Depending on the cell type it is also possible to coat the outer cell membrane with heparin or other sulphated mucopolysaccharides and to achieve similar staining phenomena with DAPI.