Pulsed Field Gradient Gel Electrophoresis, commonly known as PFGE, is a technique in molecular biology and genetics used to separate and analyze large DNA molecules. It is a specialized form of gel electrophoresis that employs a pulsed electric field to induce differential migration of DNA fragments based on their size.
In PFGE, the DNA samples are first embedded in an agarose gel. A high-intensity, pulsed electric field is then applied to the gel in a specific pattern. The electric field is generated by alternating the direction of the current at regular intervals, forming a gradient across the gel. As the electric field pulses through the gel, the DNA fragments experience varying degrees of resistance and mobility, leading to movement in different directions.
The technique allows for the separation of much larger DNA molecules, typically ranging from several kilobases to megabases in size, compared to traditional gel electrophoresis methods. By manipulating the pulse pattern, the molecular weight of DNA fragments can be estimated and compared across different samples. This information is crucial in various applications, including genetic fingerprinting, identification of genetic disorders, and studying DNA rearrangements and changes in microbial or viral genomes.
PFGE is especially useful in epidemiological studies and tracking the source of bacterial infections. By analyzing the unique DNA fragment patterns generated by PFGE, scientists can determine the relatedness of bacterial strains and trace the origin of outbreaks.
Overall, PFGE is a powerful tool in molecular biology that facilitates the separation, analysis, and comparison of large DNA fragments in various research fields.
