[The detection of provirus in lymphocyte DNA. The monitoring of HIV infection at the genetic level].

The presence of HIV provirus in the cell culture and in the patients' blood was studied by polymerase chain reaction followed by hybridization in solution. It was shown that: (i) the hybridized product could be detected both by gel electrophoresis and by binding on hydroxyapatite; (ii) the detection level achieved was no more than 10 infected lymphocytes per million; (iii) the hybridization signal and sensitivity of detection could be enhanced by the transcription of PCR product by the phage T7 RNA polymerase. The observed lack of complete correlation between the amount of provirus and of the p24 antigen in the patients' blood possibly reflects the peculiarities of HIV infection.

[Design of a DNA-matrix with a specific structure for synthesizing RNA using the polymerase chain reaction].

Combination of chemical DNA synthesis and polymerase chain reactions has been used for obtaining DNA templates of preset structure coding for target mRNAs. The obtained DNA were 136 to 246 bp in length, contained promoters for RNA polymerases of phage T7 or E. coli and coded for 136-membered mRNA.

[Synthesis of RNA using T7 RNA polymerase and immobilized DNA in a stream type reactor].

The DNA ligase-induced assembly of synthetic oligodeoxyribonucleotides on polymer supports was used to obtain immobilized DNA, containing the T7 RNA polymerase promoter and coding for a 14-membered oligoribonucleotide. The obtained template can carry out RNA synthesis in a flowing-type reactor. Sepharose 4B and Toyopearl HW-55 were used as supports.

[Cleavage of concatamer-type substrates by restriction endonucleases MVA1 and SSO1I].

The interaction of enzymes SsoII (decreases CCNGG) and MvaI (CC decreases A/TGG) with concatemeric DNA duplexes used earlier to study EcoRII (decreases CCA/TGG) TGG was investigated with a view of elucidating the general principles of the restriction endonuclease function. A pattern common for all the three enzymes was observed with DNA duplexes containing AA or TT pairs in the central position of the recognition site. The AA pair blocks or substantially hinders the endonuclease action, whereas the TT pair is either less inhibitory or altogether inert.