[2 methodological approaches to the problem of the tissue specificity of transcription]

The determination of genome transcription level in different tissues or structures of organism is carried out at present by the method of DNA--RNA-hybridization in solutions using labeled unique DNA sequences and significant RNA excess. Similar results may be probably obtained by a more simple method--numerously repeated recycles of RNA passage through the columns with denaturated DNA polymerized in agarose gel. Hybridization of single-stranded DNAs with each other is excluded and it is possible to separate RNA into fractions specific for different tissues and organs.