In MOPAC, the amino-terminal and carboxy-terminal sequences of a peptide are used to design two redundant families of oligonucleotides encoding the aminoand carboxy-terminal sequences of the peptide. The primers are used either to amplify a segment of cDNA prepared by RT-PCR from a tissue known to express the protein or to amplify a segment of DNA from an established genomic or cDNA library. - [Read Mixed Oligonucleotide-primed Amplification of cDNA MOPAC Protocol]