P212121

I have had quite a bit of luck with this trick so thought it was worth passing on.
You may have noticed that you can lose quite a bit of protein when concentrating.

Using the following steps:
1) Remove the contents from the concentrator as normal
2) Refill the concentrator with your protein’s buffer
3) Centrifuge & remove remaining solvent (if you have any)
4) Check the solution for recovered protein

Why does this work?
Precipitated and "stuck" protein that you are unable to pipette becomes soluble due to the addition of the protein’s buffer.