ABSTRACT
Conventional molecular hybridizations (Southern for DNA and northern for RNA, see Profile 12) are sometimes not sensitive enough to detect very small quantities of target DNAs or RNAs. This is the case especially for several mRNAs that are found in very small numbers in cells. PCR can be used to work with very small quantities of nucleic acids (see Profile 24). A technique called RT-PCR has been developed to detect and reveal the accumulation of a rare mRNA in an organ, tissue, or cell.
