Southern blotting is a molecular biology technique used to detect the presence of a specific DNA sequence in a sample.
It was developed by Edwin Southern and is widely used in research and clinical laboratories for studying gene expression, mutations, and DNA polymorphisms. Additionally, it is valuable in forensic analysis and paternity testing.
Principle
Southern blotting is based on hybridization, where a labeled probe binds to its complementary DNA sequence of interest for detection.
Steps of Southern Blotting
DNA Extraction: DNA is isolated from the sample.
Restriction Digestion: DNA is cut into fragments using restriction enzymes.
Gel Electrophoresis: DNA fragments are separated on an agarose gel based on size.
Denaturation: DNA is denatured into single strands using an alkaline solution.
Transfer to Membrane: The DNA fragments are transferred onto a nitrocellulose or nylon membrane.
Hybridization: A labeled complementary DNA probe (radioactive or fluorescent) binds to the target DNA sequence.
Detection: The probe-bound DNA is visualized using autoradiography or fluorescence detection.
Applications of ELISA
Detection of viral and bacterial infections.
Detection of autoimmune diseases.
Drug discovery and development.
Environmental monitoring.
