Concentrate protein from dilute solution - (Aug/10/2006 )
Hi!
I have purchased a solution of collagen, but it is at 3 mg/mL and I would like to try to concentrate it. I haven't done any dialysis before--is this the way to go? I would appreciate any details. I do not want to crystallize the collagen or anything: I am a physicist, want to have more concentrated solutions for our simple experiments (something on the order of 10-50 mg/mL would probably be desirable). I think this is probably a standard technique for trained biologists, so I hope to hear from someone! Thanks--
The easiest way, and fastest way to do it is to use a concentration column.
it's a centrifugation tube, with a membrane in the middle, that only allows small molecules to pass threw. you can have several size. I mean volume of the solution and exclusion size of the membrane.
the liquid go threw the membrane, and your protein stays in the upper part, becoming more and more concentrated.
However be careful, you loose a little of protein that will stick on the membrane.
I attach here one product file, but go to millipore website to find the one that would fit the best.
I have purchased a solution of collagen, but it is at 3 mg/mL and I would like to try to concentrate it. I haven't done any dialysis before--is this the way to go? I would appreciate any details. I do not want to crystallize the collagen or anything: I am a physicist, want to have more concentrated solutions for our simple experiments (something on the order of 10-50 mg/mL would probably be desirable). I think this is probably a standard technique for trained biologists, so I hope to hear from someone! Thanks--
Hi,
Another way is to drop the protein out of solution with a high concentration of ammonium sulfate or PEG. Then, resuspend protein in a little desired buffer and dialyze it in buffer with no salt. The dialyzed solution will increase volume a little, so must account for this.
Cindy