Pulsed Field Gel Electrophoresis (PFGE)

Download the brochure

Download the brochure: Pulsed Field Gel Electrophoresis (PFGE)

Get the latest news and insights from the world of food safety and subscribe also to our newsletter.

Download the brochure: Pulsed Field Gel Electrophoresis (PFGE)

Get the latest news and insights from the world of food safety and subscribe also to our newsletter.

Why

On several occasions, a reliable identification of a bacterial strain among several random microbial isolates is needed. This is the case, in particular, when nonsterile materials (like feeds or premixes) are examined to verify the presence of a microbial feed additive in the test material. For those purposes, the Pulsed Field Gel Electrophoresis (PFGE) can be a method of choice.

How

PFGE is an extension of the standard agarose gel electrophoresis of restriction enzyme fragmented DNA. The main difference is that PFGE can be applied to very large DNA molecules matching the size of a complete bacterial genome (3-4 million base pairs) and that it provides size-dependent resolution of large restriction fragments (up to hundreds of thousands base pairs). The approach is based on the introduction of alternating voltage gradient to the large DNA fragments. The steps in the PFGE procedure include a gentle lysis of the microbial cells immobilized in an agarose block. This is followed by digestion with a restriction enzyme belonging to the "rare cutters", which have only a small number of restriction sites in the bacterial genome. If the whole genome sequence of the strain of interest is known, this can be utilized in the selection of the restriction enzyme. After digestion, the bacterial DNA fragments, still in the agarose block, are subjected to PFGE using settings, which depend on the expected fragment size distribution. After staining, the gel is visualized and photographed. The banding pattern is compared to that of the strain of interest.

Biosafe

The PFGE method is currently undergoing standardization by the European Committee on Standardization (CEN). Biosafe Ltd has been contracted as the project lead to prepare the standard.

Request a quote or ask for more information!

You can also make an appointment for a consultation. Book an appointment on the calendar »