Differential Display: Isolation of Novel Genes

Differential display is an efficient and reproducible method for the detection of differential gene expression between a variety of cells and/or tissue populations (1 ). The approach is based on reverse transcription with oligo-dT anchored primers and PCR in the presence of the original anchor primer and an arbitrary 13-mer (2 ,3 ). Three oligo-dT anchored primers and 80 arbitrary 13-mers are used to amplify all mRNAs present in particular cells or tissues. Both primers contain HindIII sites on their 5′ ends to facilitate the cloning of the differentially expressed cDNAs. The sensitivity of RT-PCR allows for the amplification of rare messages. Additionally, several differentially expressed cDNAs can be isolated within a week. They are large enough to identify a specific mRNA, and small enough to be separated by size in standard polyacrylamide sequencing gels. The cDNAs range in size from 200 to 800 bp and represent the 3′ ends of mRNAs expressed in a particular cell or tissue type.