I hope that these articles and links will be useful.....

https://onlinelibrary.wiley.com/doi/pdf/10.1038/npg.els.0003792

http://www.pulsenetinternational.org/assets/PulseNet/uploads/pfge/PFGEPresentation6-PFGETroubleshooting.pdf

file:///C:/Users/drmoh/Downloads/TroubleshootingPFGE.pdf

Best Luck.

I hope that these articles and links will be useful.....

https://onlinelibrary.wiley.com/doi/pdf/10.1038/npg.els.0003792

http://www.pulsenetinternational.org/assets/PulseNet/uploads/pfge/PFGEPresentation6-PFGETroubleshooting.pdf

file:///C:/Users/drmoh/Downloads/TroubleshootingPFGE.pdf

Best Luck.

Gel running parameter are 6v/cm; an included angle of 120 with an initial switch time of 5 seconds and a final switch time of 45 seconds @10C for 22 hours on a CHEF ll PFGE machine (Biorad). These parameters are ideal for separating DNA of sizes of about 15kb to approximately 1 mega base. A Good plug should see a very bright band at the top of the gel and very little smearing below this.

Can you melt a small portion of your plugs and run in an agarose gel electrophoresis not necessarily doing a PFGE

Thanks Mohammed for your pdfs should be helpful.

I believe I should try prof. Mark Toleman advice. I have tried different conditions and weren't working. Could I apply the same conditions with CHIEF DR III? thanks Mark for your help.

Thanks Uzal I do need to examine the plugs using PFGE