Southern blot

Southern blot is a method used in molecular biology for detection of a specific DNA sequence in DNA samples. It was named after the British biologist Edwin Southern, who first published about the technique in 1975. The Southern blot method is used in research, clinical diagnostics, and forensic science.

Procedure

The Southern blot procedure begins with the DNA extraction from the sample. The DNA is then cut into smaller fragments using restriction enzymes. These fragments are separated by size through a process called gel electrophoresis. The separated DNA is then transferred to a membrane, a process known as blotting. The DNA fragments are then exposed to a probe - a DNA sequence with a label that can be either radioactive or fluorescent. The probe binds to the target DNA sequence and can be detected by the label.

Applications

Southern blot is used in various fields of biological research, including gene discovery, mapping, and cloning. It is also used in clinical diagnostics to detect mutations that cause genetic disorders and in forensic science to identify individuals or species.

Limitations

While Southern blot is a powerful tool, it has some limitations. It is time-consuming and requires a large amount of DNA. It also requires the knowledge of the sequence of interest to design the probe.

See also

• Northern blot
• Western blot
• Eastern blot

Southern_blot

• Southern blot process illustration
  Southern blot process illustration
• Setup of a Southern blot
  Setup of a Southern blot
• Southern blot membrane
  Southern blot membrane
• Agarose gel used in Southern blot
  Agarose gel used in Southern blot
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  Autoradiogram of a Southern blot