[Structural changes of the chromatin DNA in situ in partial deproteinization of DNP by a 0.6 M NaCl solution. A polarization-fluorescence microscopic study]. / Strukturnye izmeneniia DNK khromatina in situ pri chastichnoi deproteinizatsii DNP 0.6 M rastvotom NaCl. Poliarizatsionno-fluorestsentnoe mikroskopicheskoe issledovanie.

By means of polarization fluorescence microscopy changes in polarization degree of fluorescence of DNA-bound of Acridine orange in situ were observed. A marked decrease in polarization degree of chromatin fluorescence was found after the treatment of cell nuclei with 0.6 M NaCl. It shows that the removal of histone H1 from the chromatin results in destabilization of its structure. The data obtained show that the measurements of polarization degree of fluorescence allow to obtain relevant information about structural changes in DNA chromatin.

The use of the phosphorescence microscope for the study of the phosphorescence of various cells.

The phosphorescence microscope (i.e. a microspectrophosphorimeter) was used for recording the phosphorescence of microobjects. The general optical scheme of the reflecting phosphorescence microscope is described. The recordings of the phosphorescence spectra of cells of various types (bacteria, yeast, protozoa and human fibroblasts) were carried out both at room temperature and deep cooling. It will be shown that the phosphorescence spectra of the microorganisms are specific for every species of cells. The changes of the spectral parameters and triplet decay times after X-irradiation of Tetrahymena pyriformis cells were demonstrated. The decay time of phosphorescence of the fibroblasts at low temperature was also obtained.

[Study of nucleoside phosphorescence with a phosphorescent microscope]. / Issledovanie fosforestsentsii nukleozidov s pomoshch'iu fosforestsentnogo mikroskopa

Phosphorescence of ribonucleosides and desoxyribonucleosides is studied. The phosphorescence spectra of polycrystalline powders of adenosine, guanosine, thymidine, uridine, cytidine, desoxyadenosine, desoxyguanosine and desoxycytidine are recorded at -175 degrees C as well as the decay curves at -175 degrees C. The phosphorescence spectrum of guanosine is also recorded at room temperature. The decay times of phosphorescence of adenosine and cytidine are determined at room temperature too. Obtained values of pi for nucleosides are shorter than those for nucleic acid bases.