Free-flow electrophoretic apparatus for separation and concentration of proteins.

Protein separation in the free-flow electrophoretic apparatus with 48 channels at both the inlet and outlet using "artificial" pH gradients was investigated. The separation was carried out in borate-mannitol pH gradients and in pH gradients created by the concentration gradient of boric acid in the solutions of borax and mannitol. The separation pattern depended on the ratio of the rate of sample injection to the flow-rate of solutions in the separation chamber and did not change when the protein concentration in the sample was changed. The protein separation in the pH gradient was better than in case of conventional free-flow electrophoresis. The free-flow electrophoretic apparatus with multi-channel inlet of the separation chamber is suitable for concentration of biological materials, e.g. proteins and bacterial cells.

[Electrophoretic mobility of UV-irradiated bacterial cells]. / Elektroforeticheskaia podvizhnost' UF-obluchennykh bakterial'nykh kletok.

Electrophoretic mobility of Escherichia coli cells exposed to various doses of UV-radiation was investigated. The method of free flow electrophoresis was used to study a correlation between membrane protein charge and cell surface electric charge. The change in the cell surface charge and electrophoretic motility was associated with the damage to membrane proteins and the survival of UV-irradiated bacteria.

[Determination, by the electro-optical method, of the number of undamaged bacterial cells after extreme exposures]. / Opredelenie élektroopticheskim metodom chisla nepovrezhdennykh bakterial'nykh kletok posle ékstremal'nykh vozdeistvii.

The results of electro-optical measurements can be used to determine rapidly how the number of intact cells decreases before and after the action of certain extreme factors. The experiments were conducted with suspensions of Escherichia coli and Bacillus thuringiensis cells subjected to the action of heat, toluene, ethanol, and freezing. Electro-optical measurements can make it possible to assay the relative number of cells with both lethal and sublethal damages.

[Analysis of the changes in the electrophysical and morphometric parameters in the growth and sporulation periods of Bacillus thuringiensis]. / Analiz izmenenii élektrofizicheskikh i morfometricheskikh parametrov v period rosta i sporuliatsii u Bacillus thuringiensis.

Changes in the electrophysical and morphometrical parameters of Bacillus thuringiensis cells were studied during their growth and differentiation using the electrophysical procedure with the frequency of an alternating electric field varying within a wide range. The appearing variations were interpreted on the basis of the data about changes in the concentration of vegetative cells and spores, the optical density and pH of the cultural broth, and the assimilation of glucose by the culture. The changes found in the electrophysical and morphometrical parameters were shown to accompany the main physiological processes in the cells. In principle, they can be used to control the process of cultivation.

[Effect of dispersion of electric parameters of bacterial cells on their orientation in alternating electric fields]. / Vliianie dispersii élektricheskikh parametrov bakterial'nykh kletok na ikh orientatsiiu v peremennom élektricheskom pole.

On the basis of electrophysical model of bacterial cell frequency relationship of orienting force moment acting on it in the alternating electric field has been calculated. Dependence of relative value of the moment on electric and geometrical parameters of the model was calculated. It has been shown that the account of frequency dispersion of the electric parameters brings about a change in the course of frequency relationship of the orienting moment in the range of low and mean frequencies. The data obtained agree with electrooptic measurements performed on E. coli cells.