ABSTRACT
Measuring changes in gene expression can be a useful tool to measure endogenous cellular responses to external events, such as receptor activation. The beauty of measuring expression of endogenous genes is twofold: it can avoid patent issues that exist with some reporter gene tools, and one is dealing with a physiological event. One could also measure the effect of a compound on that event, and if the appropriate message and cell type are selected, one could potentially use gene expression as a biomarker to measure activity of a compound in the clinic. However, measuring mRNA changes in any robust moderate-throughput manner requires that the sample handling be relatively straightforward and automatable. In addition, it would be preferable that the message did not have to be isolated and that it could be measured directly, not by message amplification.
