Synthesis of saporin gene probes from partial protein sequence data: use of inosine-oligonucleotides, genomic DNA and the polymerase chain reaction.

A strategy employing the polymerase chain reaction to synthesize gene-specific probes suitable for genomic Southern analyses and for screening genomic libraries is described. The method utilizes partial amino acid sequence data from the protein of interest, genomic DNA and inosine-containing oligonucleotide primers. An example of its application for the isolation of plant gene sequences encoding saporin, a ribosome inactivating protein, is described.