Pulsed-field gel electrophoresis (PFGE)

Definition

Pulsed-field gel electrophoresis (PFGE) is a technique used to separate large DNA molecules by applying an alternating electric field. It is commonly used for typing bacterial strains in epidemiological studies.

5 Must Know Facts For Your Next Test

1. PFGE can resolve DNA fragments that are larger than those separated by conventional gel electrophoresis, often ranging from 10 kilobases to several megabases.
2. The technique involves periodically changing the direction of the electric field, which helps in achieving better separation of large DNA molecules.
3. PFGE is widely used in microbial genetics to track the source and spread of bacterial infections during outbreaks.
4. This method requires specialized equipment such as a PFGE apparatus and a cooling system to maintain constant temperature during long runs.
5. DNA samples are usually prepared by embedding cells in agarose plugs before lysing them and digesting with restriction enzymes that cut infrequently.

Review Questions

• What types of DNA fragments can PFGE effectively separate?
• How does PFGE differ from conventional gel electrophoresis in terms of electric field application?
• Why is PFGE particularly useful in epidemiological studies?

Related terms

Agarose Gel Electrophoresis: A common technique for separating smaller DNA, RNA, or proteins based on size using a constant electric field.

Restriction Enzymes: Proteins that cut DNA at specific sequences, essential for preparing samples for PFGE.

Epidemiology: The study of how diseases spread and can be controlled within populations, often utilizing techniques like PFGE for tracking pathogens.