Editing Molecular biology (section)

====Southern blotting====
{{main|Southern blot}}

Named after its inventor, biologist [[Edwin Southern]], the Southern blot is a method for probing for the presence of a specific DNA sequence within a DNA sample. DNA samples before or after [[restriction enzyme]] (restriction endonuclease) digestion are separated by gel electrophoresis and then transferred to a membrane by blotting via [[capillary action]]. The membrane is then exposed to a labeled DNA probe that has a complement base sequence to the sequence on the DNA of interest.<ref>{{cite journal |doi=10.1002/0471142735.im1006as06 |title=Southern Blotting |date=1993 |last1=Brown |first1=Terry |journal=Current Protocols in Immunology |volume=6 |pages=Unit 10.6A |pmid=18432697 }}</ref> Southern blotting is less commonly used in laboratory science due to the capacity of other techniques, such as [[Polymerase chain reaction|PCR]], to detect specific DNA sequences from DNA samples. These blots are still used for some applications, however, such as measuring [[transgene]] copy number in [[Genetically modified organism|transgenic mice]] or in the engineering of [[gene knockout]] [[Stem cell line|embryonic stem cell lines]].<ref name="Tian_2013"/>