I want to analyze BSA by using RP-HPLC. Usually my BSA protein will just be in water solution. After adding acetonitile before HPLC, there is no precipitation. But recently, my protein need to be in phosphate buffer pH 6.8. So when I mix it with Acetonitrile, it precipitate out. What should I do?
Also, I have heard that protein will precipitate out with acetonitrile. Then why most of the analytic method are using acetonitrile?
Waiting for the answers..............Thanks a lot.