ABSTRACT
The evidence that eukaryotic gene expression must be a highly regulated process is available to anyone visiting a butcher’s shop. The genetic information in the DNA specifying particular functions is converted into an RNA copy which is then translated into protein. A number of different specific methods exist that can be used to detect and quantify one specific mRNA, using a cloned DNA probe derived from its corresponding gene. In one such method, Northern blotting, the RNA extracted from a particular tissue is electrophoresed on an agarose gel, transferred to a nitrocellulose filter, and hybridized to a radioactive probe derived from the gene encoding the mRNA of interest. The primary limitation on the sensitivity of pulse labeling is the existence within the cell of a large pool of non-radioactive ribonucleotides, which are normally used by the cell to synthesize RNA. The chapter also presents an overview of the key concepts discussed in this book.
