pulsedfieldelektroforeesia

Pulsedfieldelektroforeesia, more commonly known as pulsed-field gel electrophoresis (PFGE), is a laboratory technique used to separate large DNA molecules by applying an electric field that periodically changes direction. It is designed to resolve DNA fragments that are too large for conventional gel electrophoresis, typically spanning tens of kilobases to several megabases. The term pulsedfieldelektroforeesia reflects a transliteration that sometimes appears in non-English contexts, but PFGE remains the standard designation in the scientific literature.

The technique relies on embedding DNA in a gel matrix, usually agarose, and exposing it to an electric field whose orientation is periodically altered. By changing the direction of the field, large DNA fragments reorient and migrate more slowly, while smaller fragments navigate the gel more readily, allowing size-based separation that improves with each pulsing cycle. The most common hardware configuration uses rotating or alternating fields, exemplified by contour-clamped homogeneous electric field (CHEF) systems, to generate distinct resolving conditions.

Typical workflow, described at a high level, involves producing relatively large DNA fragments (often by digesting genomic DNA with rare-cutting restriction enzymes), loading the fragments into the gel, and running the pulsed electrical field for many hours. Gels are then stained to visualize the DNA bands, which can be compared to characterize genetic relatedness among samples.

Applications are widespread in microbial genomics and public health. PFGE is a standard method for typing bacterial isolates during outbreak investigations and routine surveillance, with the PulseNet network coordinating many laboratories to compare patterns for pathogens such as Salmonella, Listeria, and Escherichia coli.

Limitations include the need for specialized equipment, long run times, and the interpretive complexity of banding patterns. Advances and alternatives, notably whole-genome sequencing, have complemented PFGE in modern genomics.