[Visualization of DNA segments, interacting with reactive oligonucleotide derivatives in interphase nuclei and metaphase chromosomes].

Reaction of (pdT)16 derivatives, bearing 4-(N-2-chloroethyl-N-methylamino)benzylphosphamide group on its 5' end and biotin on its 3' end with DNA in interphase nuclei and metaphase chromosomes has been investigated by fluorescence and electron microscopy. The result obtained evidence that in interphase nuclei DNA in active chromatin (nucleolus) is the most available for specific modification. In metaphase chromosomes the modified DNA regions are situated on the surface of chromosome.