I have been having lots of problems with my samples and reaction I need to test recently so I decided to ask for some help from more experienced people

In general the aim of experiment is to check the carbonyl groups content in proteins from photoreceptors outer segments. I just isolate outer segments and have them in PBS solution. Then to extract protein I used Folch's method and got an interphase with proteins. Problems start at this stage

Could anyone suggest some solutions? I am happy to try different methods.
I would be very grateful for your help.
Thanks,
Kinga