RT-PCR analysis of pain genes: use of gel-based RT-PCR for studying induced and tissue-enriched gene expression.

Frequently, it is important to ascertain whether a molecule that is involved in one model of pain is also involved in other models of pain. Similarly, it may be important to determine whether a molecule involved in nociception in one tissue is also expressed in other tissues and to ascertain the degree of enrichment. Additionally, before initiating a complex set of experiments or purchasing an expensive immunoassay kit, it may be useful to obtain initial supporting evidence to justify the time and money. Is the transcript for the target receptor, protein, or peptide precursor present in, for example, the dorsal root ganglion? And, if present, how abundant is it? Here is where the power of PCR can be applied to obtain a quick but informative answer. In this chapter, we mainly detail the use of gel-based RT-PCR and also provide suggestions on tissue dissection and interpretation of results. The use of gel-based RT-PCR can address many of the questions of abundance or tissue specificity with a minimum of expense and time.