Nuclear run-on analysis

Nuclear run-on analysis is a method used to measure the rate of gene transcription in vivo.

The procedure is as follows:

1. Isolate cell nuclei - when the cell is lysed for nuclear isolation, transcription complexes are stalled due to lack of NTP substrates
2. Re-start transcription with radio-labelled NTPs
3. Use autoradiography to ascertain which transcripts were stalled (and later re-started) when the cells were lysed
4. Hybridise with a gene-specific cDNA to detect which transcripts were being expressed in the cell at that time

This technique can be used to compare patterns of gene transcription in nuclei of different cell types, or at different times.