Characterizing cDNA Ends by Circular RACE

Rapid amplification of cDNA ends (RACE) is a widely used PCR-based method to identify the 5′ and 3′ ends of cDNA transcripts from partial cDNAs. While conceptually simple, this method often requires substantial optimization before accurate end identification is achieved. This is due in part to the anchoring of a universal primer to a cDNA or mRNA for PCR, which can lead to the generation of nonspecific amplification. Here, we describe an improvement of the original RACE method, circular RACE, which can be used to simultaneously identify both the 5′ and 3′ end of a target cDNA.