A molecular biologist used restriction enzyme for digesting a specific sequence of DNA, which molecular biology procedure he would be using to separate the DNA fragments?
Agarose gel electrophoresis is the technique of separating DNA fragments on the basis of their molecular weight. Smaller fragments move faster than larger ones; the distance migrated by the DNA on the gel is inversely proportional to the molecular weight. DNA is isolated by performing the cell lysis using a group of enzymes and solvents leading the the constituents to come out of plasma membrane along with the DNA. DNA is precipitated out from the cell lysate by adding chilled ethanol. The purified sample is further treated with endonuclease causing the fragmentation of DNA. Then the DNA fragments are separated by gel electrophoresis.
The Enzyme-Linked Immunosorbent Assay (ELISA) is an immunological assay which is used to detect the presence of molecules like antibodies, antigens, proteins and glycoproteins in any biological sample. It works on the principle that specific antibodies will bind to specific antigens.
Southern blotting is a technique which involves the transfer of DNA fragments from the agarose gel to nylon or nitrocellulose sheet. This is then utilised to visualize the desired DNA sequences by allowing hybridisation with a radioactive probe. This is commonly used in DNA fingerprinting technique.
DNA fingerprinting is a laboratory technique used to analyse the genetic makeup of the person or living beings. It employs the techniques such as Polymerase Chain Reaction (PCR), Gel electrophoresis and Southern blotting. One of the applications is to establish a link between a biological sample and a suspect in a criminal investigation.