After performing dialysis on nitrocellulose membrane (Slide-A-Lyzer MINI device, MWCO = 20K) concentration of my protein (CmGRP) dropped basically to zero. It is most likely that protein sticks to the dialysis membrane during the process. Is there a solution to that problem?
Thank you in advance
Dialysis membrane is usually made of regenerated cellulose or cellulose acetate, not nitrocellulose. The rest of the device is probably made of polypropylene. Neither of the materials is particularly bad for nonspecific protein adsorption.
The problem could be that the protein is unstable in the dialysis buffer, precipitating or degrading, rather than sticking to the surfaces of the device.
However, if it is just sticking, try including a low concentration of a nonionic detergent such as 0.005% Triton X-100, Tween-20 or Brij-35 in the sample and dialysis buffer to coat the plastic surfaces and any exposed hydrophobic patches of the protein.
Additional to the above suggestion, if an additional protein is not a problem for your downstream application, you may also add carrier protein such as BSA to your protein solution to test the non-specific binding decrement.
- Badges
- Science topic
- Similar topics
- Engineering
- Chemical Engineering
- Membranes