Use of ultrasonic standing wave in biological studies and cell technologies.

In experiments on rat erythrocytes and yeast cells, we studied processes of concentration, separation, and isolation of native cells in suspensions by using standing ultrasonic wave field. Fifteen parameters essential for these processes were determined, and the applications of ultrasonic stratification, concentration, and cell separation methods under experimental conditions were determined.

[The role of temperature as a factor of structure and functional fit of a "prey" virus based on the example of phage T4].

By means of high-precision acoustic measurements and by the methods of fluorescent and electron microscopy investigations were performed of thermoinduced conformational changes in T4 bacteriophage and its thermolabile mutants altered in baseplate proteins (gene products "7", "8", "10"). A relationship was found between the conformational changes in T4 bacteriophage structure in the temperature range of 33-45 degrees C and the efficiency of bacteriophage adsorption and changes in the orientation of long tail fibers. Possibility of heat regulation of "recognition" of "host" cells by bacterial viruses is suggested.

[Study of antibody-hapten interaction by measuring velocity of ultrasound propagation].

The patterns of conformational changes induced in pig antibodies to 2,4-dinitrophenyllisin on binding with hapten were investigated by precise measurements of ultrasound velocity. It was shown that upon specific binding with intact antibodies, the observed slow changes of the bulk-clustic properties of the investigated solution reflect self-association of IgG molecules. In the case of interaction of Fab-fragments with hapten no changes of the acoustic properties were found.