[en] Full text: Search for novel technologies in biology, application of up-to-date methods in gene engineering, manipulation with the recombinant DNA, in particular, open opportunities for experiments with plants. To identify some DNA fragments in an organism's genome, radioautographic methods, such as dot- and blot-hybridization are frequently used. As a rule, genomic DNA is first isolated from the plant's organ. Its purification and subsequent manipulation is followed by hybridization with a probe labeled with radioactive components. The purified DNA, cDNA of RNA reverse transcription or a DNA fragment cloned in E-coli could serve as the probe. Radioautography shows homologically hybridized fragments. We have performed express dot-hybridization analysis on hybrid plasmid transformation of G.Hirsutum L. (108F) and G. Barbadense L. (C-6037) cotton sorts. pCaVItoxneo plasmid obtained on the basis of independently replicated plasmid-like DNA of the G.Hirsutum L. (pGHm2) cotton mitochondria was used (Yusupov T., 1994). There are hybrid two-domain gene of insectotoxin and enzymatically active kanamycine - phosphotransferase in the plasmid. The whole content is controlled by the plant promoter of cauliflower mosaic virus (19 S SFMV). The plasmid in question was added to the pollen sprouting medium followed by the transfer of the suspension on the pistil stigmas of the pre-prepared cotton flowers. The seed budding as the result of the experiment were analyzed by means of dot-hybridization method. DNA probes used for radioactive hybridization were labeled by method of Fainberg and Vagelstein (1990). To perform that DNA was dissolved in Tris-EDTA (10:1), containing 10mM of Tris HCl and 1mM EDTA, denaturated at 100^deg^C for 2 minutes with subsequent addition of oligonucleotide primers and annealing. DNA synthesis in the presence of ³²P labeled dATP and dCTP (Tashkent) was performed in the reaction mixture of potassium-phosphate buffer containing 67mM of MgCl₂, 1 mg/ml of BSA, 1mM methyl ester, 0.5mM of GTF and TTF, 10-20 mkCu of dATF and dCTF labeled with ³²P, 2.5 Units of activity of Klyonov's fragment (DNA polymerase I). Radioactive phosphorous inclusion percent was determined by means of following successive washing of filters from the labeled mixture with phosphate buffer and ethanol. As the result of 20 G.Hirsutum L. and 44 G. Barbadense L plants grown from the experimental seeds 12 and 25 versions of positive dot-hybridization signals were respectively obtained. This is to be the evidence for integration of hybrid plasmid into the genome of experimental plants. The subsequent generation DNA was treated with the Hind III and BamH I restriction fragments to perform blot-hybridization. Thus, radioautography has been found important for analysis of genome of experimental plants without signs morphologically manifested. (author)