Analysis of gene expression in single cells.

A cell's structural and functional characteristics are dependent on the specific complement of genes it expresses. The ability to study and compare gene usage at the cellular level will therefore provide valuable insights into cell physiology. Such analyses are complicated by problems associated with sample collection, sample size and the limited sensitivity of expression assays. Advances have been made in approaches to the collection of cellular material and the performance of single-cell gene expression analysis. Recent development in global amplification of mRNA may soon permit expression analyses of single cells to be performed on DNA microarrays.