title: [Use of DNA-methylases as reagents for the production of isotopically labeled DNAs].
abstract: The method of incorporation of an isotopic label into DNA by means of DNA-methyltransferases (DNA-methylases) is proposed. DNA was no degraded and retained its biological activity in the DNA-methylase reaction. The specific activity of labelled DNA preparations can be increased, using the mixtures of different DNA-methylases in the enzymatic reaction. An isotopic label was incorporated into DNA, using DNA methylases M. .EcoRII, M.Eco dam and M.EcoMRE600 dcmI. An average activity of 1 microgram of labelled DNA preparations produced by S-adenosylmethionine (methyl-3H) with specific activity of 15 CU/mmol mas about 1 x 10(5) cpm.
mesh_terms: D004247:DNA; D004248:DNA (Cytosine-5-)-Methyltransferases; D007202:Indicators and Reagents; D007553:Isotope Labeling; D008780:Methyltransferases; D011865:Radioisotope Dilution Technique; D012436:S-Adenosylmethionine; D014316:Tritium
chemical_list: D007202:Indicators and Reagents; D014316:Tritium; D012436:S-Adenosylmethionine; D004247:DNA; D008780:Methyltransferases; D004248:DNA (Cytosine-5-)-Methyltransferases
vernacular_title: Ispol'zovanie DNK-metilaz v kachestve reagenta dlia polucheniia mechennykh izotopami DNK.