Efficient extraction of RNA from vascular tissue.

The development of new and effective techniques to study differential gene expression has revolutionized biomedical research during the last decade. Such techniques include differential display reverse transcription polymerase chain reaction (ddRTPCR) (see Chapter 9 ), first described in 1992 (1), cDNA representational difference analysis (cDNA RDA) (see Chapter 8 ), first described in 1994 (2), and serial analysis of gene expression (SAGE), first described in 1995 (3). All have the potential to be powerful tools in the study of gene expression in healthy and diseased vascular tissue. The starting material in all these gene expression studies is high quality RNA. However, it is widely realized that the efficient extraction of such RNA from vascular tissue is difficult, for reasons that will be described later. The majority of studies on gene expression in vascular disease to date have used cultured vascular cells (4-6), as the RNA extraction is easier and the yield greater than from solid tissue. However, cell culture per se induces changes in gene expression, and so the use of the intact tissue would be a more valid approach for studying gene expression in vascular disease.