[Polyphotobiotin--a new reagent for introducing biotin into nucleic acids]

A new reagent, polyphotobiotin (PPhB), for labelling DNA probes has been obtained using low molecule oligoethylenimine (M 600 Da). Photoreactive group of PPhB is 4-azido-salicylic acid. The procedure is simple and quick, the reaction time being about 20 min. PPhB-labelled DNA has the same efficiency in the hybridisation analysis as DNA labelled with Bio-4-dUTP via PCR.