SEMIQUANTITATIVE PCR - A TOOL TO STUDY LOW ABUNDANCE MESSAGES IN THE KIDNEY

Some specific functions are often localized to unique cellular types o r structures in organs such as kidney, brain, blood, and endocrine gla nds. As a result, it is not uncommon that gene products, although heav ily expressed in some cell types within these organs, ultimately appea r as low abundance products when total RNA is probed, resulting in dec reased power of the conventional Northern blot analysis. To study gene expression in these circumstances, more sensitive techniques like RNA se protection assay and quantitative or semi-quantitative PCR strategi es have been developed. In the present study, we provide a detailed de scription of the semiquantitative PCR strategy in our laboratory. Usin g specific primers to amplify fragments from the neuronal isoform of t he nitric oxide synthase and the thiazide-sensitive Na+:Cl- cotranspor ter (low abundance messages in the kidney), we show that the semi-quan titative PCR strategy is a valuable tool when low abundance messages a re to be studied.