desalting resin - (May/17/2013 )

we have sephadex g-25, sephadex g-50 and sephadex g-75 resins. our protein is 20 Kda and we would like to desalt it for further processing. Can some one recommend which of these will be suitable. i.e which will cause less dilution and better desalting.

we would be packing them in XK 16/40 column and use for desalting so what amount of sample can be desalted at a time.

kindly suggest

thanks

of those choices, sephadex g-25 would be your best bet. you want your protein in or near the void volume, the salts will trail.

for desalting, you should load no more than 30% of the column volume (i would recommend no more than 10%).