摘要:
The type III restriction enzyme EcoP15I is used to isolate from cDNA of an expressed gene a tag comprising more than 25 nucleotides and capable of identifying the expressed gene, wherein the 3′ end of the tag is defined by a cleavage site of the type III restriction enzyme and the 5′ end of the tag is defined by the cleavage site of another restriction enzyme that is closest to the 3′ end of the cDNA of the expressed gene. The tag of the invention allows accurate quantitative gene expression analysis and rapid gene expression profiling in any organism for which no expressed sequence tag (EST) database is available.