Gene expression analysis by transcript profiling coupled to a gene database query

We describe an mRNA profiling technique for determining differential gene e xpression that utilizes, but does not require, prior knowledge of gene sequ ences, This method permits high-throughput reproducible detection of most e xpressed sequences with a sensitivity of greater than 1 part in 100,000, Ge ne identification by database query of a restriction endonuclease fingerpri nt, confirmed by competitive PCR using gene-specific oligonucleotides, faci litates gene discovery by minimizing isolation procedures. This process, ca lled GeneCalling, was validated by analysis of the gene expression profiles of normal and hypertrophic rat hearts following in vivo pressure overload.