Many organisms, including humans, have many more proteins than are actually coded for by their genes. This discrepancy is partially explained by the existence of alternative transcripts produced by the same gene. Multiple isoforms of the same gene sometimes perform completely different functions, and as such, knowing the sequence of one of the transcripts is not enough. Rapid Amplification of cDNA Ends (RACE) provides an inexpensive and powerful tool to quickly identify alternative transcripts of a gene when the partial or complete sequence of only one transcript is known. In the following sections, we outline details for rapid amplification of 5' and 3' cDNA ends using the "New Race" technique.