Hi I have this antibody that I need to run on gel. But it's been purified under high salt conditions (0.5M NaCl). I know that the gel will give me problems if I run it under the high salt. However, I have been told I can microdialyze my protein. but how??

I dialyzed my antibodies against PBS using the Pierce Slidealyzer

http://www.piercenet.com/products/browse.cfm?fldID=040101&WT.mc_id=keyname

Yes, I've used the Slidealyzers too - they are excellent for small volumes. If you have larger volumes you might want to use a de-salting column. I used to use PD-10 columns for de-salting Adenovirus preps - there should be something available from ye olde Pharmacia (GE Healthcare now - I think).