Strange protein transfer - (Nov/04/2005 )

The developed membrane of a cowkorker shows a normal rainbow, but there is no band for his protein. However, there are dark circular blotches that align perfectly with the holes in the cassette used to make the gel sandwich. Any clue what may have occurred during transfer?

Thanks!

lack of adherence and lack of uniform pressure can alter the transfert of proteins...
Try to put a cow up on the cassette to ensure good pressure

I have exactly the same problem! I do everything the same, but this still happens once a while. Very frustrating.

I agree with Fred, sounds like a lack of transfer due to the membrane not being in full contact with the gel. Can't explain the blotches though. I have had dark areas appear on films that I have exposed, that were due to the chemiluminescent substrate leaking out of the plastic membrane sandwich andbetween the sandwich and cassette forming bubbles, that showed on the film.

Cheers,
Bob