Difference Between Southern Blotting and Northern Blotting


Primary Difference

Some of the people are not able to figure out the actual difference between the Southern and Northern Blotting easily. Therefore right in this article we will be explaining the complete concept about the comparison of and Northern Blotting, their working concepts and their main differences. Do you know what is the main difference between the Southern and Northern Blotting? Southern blotting is defined to be a method that is mainly used at the time when we want to search out for the appearance of any sort of particular DNA fragment in a given sample. But on other side the northern blotting is a process that is used for the purpose of the detecting RNAs that is all found to be separated by the process of electrophoresis. Southern Blotting is a process that is on the normal basis carried away by the use of the molecular biology. Its main purpose is to check in support of the presence of a DNA sequence in a DNA sample. Southern blotting is the combination of the agarose gel electrophoresis in support of the size separation of DNA in the company of some methods. They use these methods just to transfer the size-separated DNA right into the filter membrane for probe hybridization. On the contrary side Northern blot is defined to the method that is much used in the molecular biology research just for the sake to carry out the study work of the gene expression. Well the main difference that is witnessed in this method is related to the addition of the addition of formaldehyde in the agarose gel that performs the role of denaturant. In the process of the Northern blotting the substrate nucleic acid is considered to be the gathering of the isolated DNA fragments. It is all extracted from a tissue and radioactively labeled.

Comparison Chart

Southern BlottingNorthern Blotting
Southern blotting was developed for the very first time by the E.M. Southern in 70’s.This method was developed by the Alwine and his colleagues in 70’s.
The separation of DNA will take place.Separation of RNA will take place.
Need of Denaturation.No need of Denaturation.
DNA-DNA hybridizationRNA-DNA hybridization

Definition of Southern Blotting

Southern blotting was developed for the very first time by the E.M. Southern in 70’s. In southern blotting is all about the DNA that is hence all extracted from the human cell. Afterwards it is all cut into fragments all the way by using the assistance of the restriction enzyme. As soon as these all fragments are separated by the way of using the process of electrophoresis. Then they will be transformed into bands that are included with so many copies of that DNA. You can even make these bands visible by the method of some specific staining. After sometime these bands will be transferred to nitrocellulose filter. At that point solution is made that is used at the stage of passing through the gel and even filtering the paper towel. This whole method will be coming up with the production of the nitrocellulose filter with the means of DNA fragments that is all transferred to the filter. This method in short gives out the complete information on the concept of DNA size and identification.


Definition of Northern Blotting

On the next we will be discussing about the northern blotting! This method was developed by the Alwine and his colleagues in 70’s. In this method the RNA is extracted right from the presented sample. You will view that right through the functioning of this method Electrophoresis will take place and then RNA will get separated by the size. Hence at the end of the process the RNA will get shifted to the membrane and will get fixed by using the UV light and heat. Right into this method the extraction of RNA is done with the company of electrophoresis and then hybridization. Its functioning has been very much difference from the Southern blotting because it is related with the functioning of the RNA and has no concern with DNA.

Differences in a Nutshell

  1. Southern was the one who introduced this technique of southern blotting. Northern blotting was developed by the Alwine.
  2. In the Southern Blotting the separation of DNA will take place and in Northern Blotting separation of RNA will take place.
  3. There is no need of Denaturation in northern blotting but it is considered to be very much important in the southern blotting.
  4. Nitrocellulose filter membrane is utilized in the method of southern blotting but it is not needed in the northern.
  5. DNA-DNA hybridization will going to take place in the southern blotting. RNA-DNA hybridization usually happens in the method of northern blotting.
  6. Amino benzoyloxymethyl filter paper is used in the method of the northern blotting but you don’t need to utilize it in the method of southern blotting.


Two terms which are rather unknown to people and even to the ones who are related to the subject. This article has therefore, laid out the main points about them, gave enough detail so that people are able to understand and then explained the differences between them which will make the scope of them clear.

Aimie Carlson

Aimie Carlson is an English language enthusiast who loves writing and has a master degree in English literature. Follow her on Twitter at @AimieCarlson