[Uniparametric analysis of chromosomes from human fibroblasts using flow cytofluorometry].

Metaphase chromosomes from human diploid fibroblasts were isolated by the polyamine method and stained with different fluorochromes: propidium iodide, chromomycine A2, bisbensimide H33258, and DAPI. The fluorescently stained chromosomes were analyzed using a cell sorter ATC-3000 ("Bruker-Spectrospine"), and the flow histograms were investigated to identify the peaks of individual chromosomes and to choose the chromosomes which can be isolated to a high purity. High resolution was obtained with H33258 or DAPI.

[Genomic DNA as compact particles: morphology, biochemical analysis and optical properties].

Compact DNA particles have been obtained by a new method we developed to isolate high-molecular-weight DNA. The method includes exhaustive proteolysis while the cellular DNA is folded in compact state in polyethylene glycol-containing aqueous-salt media. The DNA particles derived from interphase nuclei have a diameter of 8-10 microns and each of them contains the genome of an individual cell.

[Electron microscopic study of changes in chromosomal structural organization under the effect of formamide].

Isolated human metaphase chromosomes were treated with formamide at different (0-70%) concentrations and examined electronmicroscopically by protein monolayer technique. At increasing formamide concentration chromosomes gradually decondense, the scaffold becomes more clearly visible, the loops of chromatin fibres coming off the central part of chromosomes lose their nucleosomal appearance. Electrophoretic analysis of chromosomal proteins data show that formamide-treated chromosomes have approximately the same histone content as those before treatment, although chromosomes treated with 70% formamide look very similar to histone-depleted ones described elsewhere.

[Patterns in the occurrence and the submicroscopic organization of elongated metaphase chromosomes isolated from the cell].

Chinese hamster metaphase chromosomes were investigated under different conditions of isolation. Light microscopic study demonstrated different forms of stretched chromosomes, from those in which merely a small region is stretched to rope-like structures 20-25 microns long with diameter of about 0.4 micron.

[Residual structures revealed after the action of staphylococcal nuclease on decondensed metaphase chromosomes].

The isolated Chinese hamster metaphase chromosomes were decondensed in 0.6 M NaCl solution and digested by staphylococcal nuclease on electron microscope grids. The residual structures as seen in electron microscope as isolated aggregates scattered over the entire area occupied by the chromosome.