Analysis of gene expression : reverse transcription-polymerase chain reaction

Numerous techniques have been developed to measure gene expression in tissues and cells. These include coupled reverse transcription and polymerase chain reaction amplification (RT-PCR), Northern blot (see Chapter 20 ), in situ hybridization (see Chapter 21 ), RNase protection assays, dot blots, and S1 nuclease assays. Of these methods, RT-PCR is the most sensitive and versatile (1-bi1-5). PCR allows amplification of a DNA or cDNA template by greater than one million-fold quickly and reliably (6). Starting with minute amounts of DNA, PCR generates sufficient material for subsequent experimental analyses such as cloning, restriction digestion, electrophoresis, and sequencing. The entire amplification process is performed in just a few hours.