Are you close to the theoretical isoelectric point of your protein ? Change pH of buffer Jürgen
...................... Jürgen Bosch Johns Hopkins Bloomberg School of Public Health Department of Biochemistry & Molecular Biology Johns Hopkins Malaria Research Institute 615 North Wolfe Street, W8708 Baltimore, MD 21205 Phone: +1-410-614-4742 Lab: +1-410-614-4894 Fax: +1-410-955-3655 http://web.mac.com/bosch_lab/ On Jan 28, 2012, at 10:55, "rashmi panigrahi" <rashmi.panigrah...@gmail.com> wrote: > Hi all, > I tried to concentrate my protein using vivaspin 20 10,000 MWCO PES. > The protein was in 50mM Hepes pH 7.5, 500mM KCl and 10% glycerol. > I lost about 90% of my protein on the membrane of the centricon. > > Please suggest some way of concentrating this protein. > Will concentrating using peg 20K be a good alternative?? > > regards > > rashmi
