Southern Blotting Plays an Important Role in Various Healthcare Industry Verticals

Southern blotting is a laboratory technique used in molecular biology to detect specific DNA sequence in a blood/tissue sample. This technique was first reported in 1975 by E.N. Southern and is based on the hybridization, a process whereby a single stranded DNA is converted into a double stranded DNA by combining it with a single stranded target DNA. Southern blotting mixes the single transfer of purified DNA molecules onto a purified filter membrane and then subsequent hybridization with a restriction enzyme. This method can be used to detect DNA abnormalities or sequence variations that are specific to the region of interest.

 

Southern blotting has gained significant momentum over the years and has played a wide role in various healthcare industry verticals, in clinical trials and diagnostic purposes. The technique also helps in detecting some chronic diseases, cancer and genetic diseases, prevalent around the world. For instance, chronic diseases such as cancer, diabetes, and cardiovascular disease are the leading causes of death and disability in the U.S., according to the Centers for Disease Control and Prevention (CDC).

Southern blotting involves separation of electrophoresis-fused DNA fragments into a stain-coated cell membrane and subsequent blotting on a blotting paper. The intensity of the coloration will depend on the sequence of DNA that has been detected. In more recent years, southern blotting hybridization has gained popularity as a technique for DNA profiling. A southern blot hybridizes to the DNA of one DNA source with an unknown mixtures of DNA of different sources.

To perform this process, the DNA of one sample is mixed with a dye complementary to the origin of the DNA and an agarose gel (agarose containing DNA) is gently added to the reaction mixture. After about 10 minutes, the DNA is separated from the agarose gel using a rinsing method. Then, either single stranded or double stranded DNA fragments are isolated using the method described above. Southern blotting allows detection of small molecules such as viruses and bacteria. The presence of multiple DNA sources allows for the probability of more genetically significant fragments to be discovered when two or more independent experiments are run on the same samples. Moreover, Southern blot hybridization can be performed with DNA of very low quality, which greatly improves the chances of obtaining a reliable result.