Technique yields a heterogeneous population of short radiolabeled molecules 200-300 nucleotides in length. These probes are synthesized, as in Synthesis of Single-stranded DNA Probes of Defined Length from Bacteriophage M13 Templates, by extension of an oligonucleotide primer on a single-stranded DNA template. The radiolabeled products of the reaction are then separated from the template by electrophoresis through a denaturing gel from which they are eluted directly into hybridization buffer.
