[Use of immunoenzyme analysis on nitrocellulose membranes for assessing different methods of purifying the yellow mosaic virus of beans]. / Ispol'zovanie immunofermentnogo analiza na nitrotselliuloznykh membranakh dlia otsenki razlichnykh sposobov ochistki virusa zheltoi mozaiki fasoli.

The comparative study of different methods for the purification of bean yellow mosaic virus isolated from lupine has been made. To evaluate the method of purification, electron-microscopic, spectrophotometric and ELISA techniques have been used. The possibility of using ELISA on nitrocellulose filters with the utilization of a peroxidase-antiperoxidase complex, manufactured in the USSR, for the determination of viral carriership in plants has been shown.

Role of the heterogeneity of A/Hong Kong/1/68 (H3N2) influenza virus populations in establishment of persistent infection of L cells.

Three subpopulations of A/Hong Kong/1/68 (H3N2) influenza virus differing from one another in biological properties obtained by elution from DEAE-Sephadex with phosphate buffer containing increasing concentrations (0.1, 0.5 and 1 mol/l) of NaCl, were used to induce persistent infection of L929 mouse fibroblast cells. In the course of 25 passages, cell destruction occurred only at low passage levels, especially in the LA-68/0.5 and LA-68/all. sublines. The proliferating activities of LA-68/0.1 and LA-68/1.0 were higher than those of the other two sublines. The size of cell nuclei in all infected sublines was increased. Influenza virus antigen was demonstrated by immunofluorescence in cells of all sublines. The virus was recovered irregularly and only at some passage levels: after 2, 2 and 5 chick embryo passages from the LA-68/0.5, LA-68/0.1 and LA-68/1.0 cells, respectively. The viruses recovered from the LA-68/1.0 subline possessed the lowest haemagglutinating activity against various animal erythrocytes.

Ultrastructural localization by immunoperoxidase techniques of influenza virus antigens in abortive infection of L cells.

An abortive infection was induced in L cells by influenza virus A/Hong Kong/68 (H3N2). With the use of antibody and peroxidase-labelled protein A, the localization of virus protein synthesis but not the maturation of virus particles was demonstrated at the ultrastructural level. Five days after inoculation (p.i.), the synthesis of viral haemagglutinin was localized in the region of the rough endoplasmic reticulum; at late intervals p.i., haemagglutinin accumulated in the plasma membranes, where membrane vesicles, containing haemagglutinin in their membranes, were released from the cell surface. The cytoplasmic viral ribonucleoprotein was localized in the region of free cytoplasmic ribosomes and that of the outer sheet of the nuclear membrane. Viral proteins were detected in the cytoplasm and plasma membranes also after 70 and 390 days of passaging of the cells or of their long-term cultivation with regular change of medium.