Gene transcript profiling in aging research.

Advances in biotechnology have led to methods for quantifying the relative concentrations of thousands of mRNAs in parallel. While these are powerful methods that can be used for both hypothesis testing and hypothesis generation, gene transcript profiling has some limitations as a tool to study aging. These include the difficulty in separating effects of aging from analytical and biological variability, statistical problems associated with simultaneous determination of so many different gene transcripts, and uncertainty about the functional significance of changes in mRNA concentrations. In this review, these issues are discussed with a focus on two methods for profiling mRNAs--serial analysis of gene expression (SAGE) and DNA arrays.