protein separation by filtration - (Mar/30/2010 )

hello i posted a question last month no reply to it. i want to separate 290000 Dalton protein from 1000-4000 Dalton range protein in a solution by filtration under vacum. what kind of paper filter i can use?

the procedure don't tell about the pore size . i have 0,450 micron pore paper ? it can be good ...?

where i can find relation between Dalton and nanometer?

silvergold31 on Mar 30 2010, 10:01 AM said:

Your proteins will go right through 0.45 um paper. You need some ultrafiltration membranes or columns. You can find them at Millipore, I don't know of any other companies that have good filters for such tasks.

http://www.millipore.com/catalogue/search....stId=7DCG6T#0:0

Depending on what volume you need, the products can be pretty reasonable to really expensive. There are many molecular weight cutoffs available, anywhere from 1-1000 kDa.

I know that this is not the right post, but I do not know how to make a new post and I need help with serum starving some cells. I have been trying to serum starve some BRE cells and for some reason they are lifting off the plate( I do not believe they are dead). I wash them with PBS before putting in the serum free media. I have 500 ml of serum free media and it has has 50ml of 1% BSA. When I place the serum free media into the dishes, the cells are fine for a while, but then lift up.

Dialysis tubing is cheap. You could try that route first.