[Detection of the provirus of the bovine leukemia virus in bovine peripheral blood leukocytes by means of DNA hybridization]. / Obnaruzhenie provirusa virusa leikoza krupnogo rogatogo skota v leikotsitakh perifericheskoi krovi krupnogo rogatogo skota metodom DNK-gibridizatsii.

The method allowing the detection of BLV proviral DNA in the peripheral blood leukocytes of cattle is reported. Cell DNA from leukocytes used without preliminary cultivation was dot-hydridized with 32P-labeled plasmid that included a fragment of BLV proviral DNA. In parallel, sera from the cattle under study were tested by immunodiffusion assay (ID). The results indicate that dot-hybridization assay is more sensitive as a diagnostic test than ID because it detects BLV infection in apparently normal cattle which was seronegative by ID.

[Use of an immunoperoxidase method in situ for detecting recombinant clones of vaccinia virus containing an expressed gene of influenza viral hemagglutinins]. / Ispol'zovanie immunoperoksidaznogo metoda in situ dlia vyiavleniia rekombinantnykh klonov virusa ospovaktsiny, soderzhashchikh ékspressiruemyi gen gemaggliutinina virusa grippa.

The vaccine L-IVP strain of vaccinia virus (VV) was used to construct the recombinant viral clones containing the influenza A hemagglutinin gene. The recombinant T plasmid was obtained with HA gene inserted in the vector pGS-20 (B. Moss) under the 7.5 K promoter of VV. A homologous recombination technique was used to insert the gene with the flanking TK sequences into vaccinia virus genome. The recombinant clones were selected by dot-hybridization with [32P]-labeled HA-probe. These recombinants were analysed for HA gene expression by the indirect immunoperoxidase method in situ using the peroxidase conjugate of the staphylococcal A-protein. This technique allows to obtain stable stained preparation and analyse the protein behavior at the ultrastructural level.