DNA microarrays and beyond: completing the journey from tissue to cell.

For the cell biologist, identifying changes in gene expression using DNA microarrays is just the start of a long journey from tissue to cell. We discuss how chip users can first filter noise (false-positives) from daunting microarray datasets. Combining laser capture microdissection with real-time polymerase chain reaction and reverse transcription is a helpful follow-up step that allows expression of selected genes to be quantified using sensitive new in situ hybridization and immunohistochemical methods based on tyramide signal amplification.