I have prepared a stock of rehydration buffer containing 7 M urea, 2 M thiourea, 4% CHAPS, 1.5% SB-12, 65 mM DTT, 0.1% protease inhibitor cocktail, and 0.1% Ampholyte. Then, I aliquoted the solution in 500 microliter volumes and stored it in a -20 freezer. I thaw one of the liquids whenever I want to dissolve my proteins in the rehydration buffer. However, rehydration buffers are consistently tricky to become transparent. Rehydration buffers are usually cloudy even when warm to 37 degrees centigrade. Could you let me know if it is normal? How can I resolve this problem?
To prevent rehydration buffer crystallization in 2-D electrophoresis, store the buffer at an appropriate temperature, avoid evaporation, use fresh solutions, and ensure proper sealing during storage and use.