Northern blot

This is a Northern blot is a technique designed to identify mRNA in tissues and not DNA. Hence it is able to pick transcripts of genes when such are present and therefore able to determine where genes are expressed or derepressed. If Northern blot is positive, it means that the gene product is produced in the cell or tissue under study. It is therefore a valuable tool in research where new peptide products are being sought for and found daily.

mRNA is extracted from the nucleus and subjected to restriction enzyme to produce several restriction fragments. One of the fragments contains the transcript to be identified. They are subjected to agarose gel electrophoresis. The resulting gel is blotted on to DBM (diazobenzyloxymethyl) paper rather then nitrocellulose filter since nitrocellulose filter does not have affinity for RNA. The DMB paper is already impregnated with gene probe which is radiolabeled. The area of resulting hybridization is picked up by autoradiography.


Northern blot



Cell types

Organ integration



Chemical Pathology


Molecular biology




Electronic School of Medicine
Creator: Oluwole Ogunranti