Background: Rapid amplification of cDNA ends (RACE) is a polymerase chain reaction-
based technique which facilitates the cloning of full-length cDNA
sequences when only a partial cDNA sequence is available. Traditionally,
cDNA sequence is obtained from clones isolated from plasmid or
phage libraries. Frequently these clones lack sequences corresponding to
the 5' ends of the mRNA transcripts. The missing sequence information
is typically sought by repeatedly screening the cDNA library in an effort
to obtain clones that extended further towards the 5' end of the message.
The nature of the enzymatic reactions employed to produce cDNA
libraries limits the probability of retrieving extreme 5' sequence even
from libraries that are very high quality.