AAT Bioquest

What is the major difference between Northern and Southern blotting?

Posted April 24, 2020


While both techniques are used to identify nucleic acid sequences, Northern blotting is performed to detect RNA sequences, while Southern blotting is done to detect DNA sequences. The processes for each are similar, involving gel electrophoresis, transfer to a membrane, and hybridization. However, while agaroses gel are typically used for electrophoresis in Southern blotting, formaldehyde or polyacrylamide gels are commonly used in Northern blotting. Southern blotting also requires DNA to be digested with restriction enzymes before running the gel; this is not necessary for RNA in Northern blotting.

Additional resources

Brown, T. (2001). Southern Blotting. Current Protocols in Immunology, 6(1). doi: 10.1002/0471142735.im1006as06

He, S. L., & Green, R. (2013). Northern blotting. Methods in enzymology, 530, 75-87. doi: 10.1016/B978-0-12-420037-1.00003-8