Unknown silver/grey residue left after transfer.
Posted 10 August 2012 - 03:08 PM
Today while transferring proteins from a 15% SDS gel to a PVDF membrane something very strange happened. After the membrane was soaked in methanol, running buffer, etc. it was placed in the sandwich with the gel that contained a ladder and various proteins using standard protocol. The transfer was set up to run at 80V for about 1.5hrs, in the four degrees Celsius room and after it was "completed" and the sandwich was opened, the membrane had a large amount of unknown silver/grey reside on it and the ladder (which was visible with very high resolution on the SDS gel) looked degraded (i.e. they were not even) on the gel, and was very blotchy looking on the membrane it self (i.e. the lines were not defined, and were only partially there).
This residue was all over the membrane in swirls and looked very random (somewhat comparable to monotone a Jackson Pollock painting). Anyways, after a really crummy day in the lab where everything I touched seemed to fail, having this Western do this was the last thing I really needed. Any ideas on why this happened are gladly welcomed. Thank you.
Posted 12 August 2012 - 02:42 PM
Posted 12 August 2012 - 08:44 PM
I would suspect residues of something on the pads, and perhaps not close enough contact between the gel and membrane, leading to the north-western effect, where a small amount of transfer fluid gets between the gel and membrane and swirls around during transfer.
Interesting, I didn't know about this effect. Thanks for the input!