Transferring crystal into mother liquor minus lithium sulfate plus ligand may work (consider both direct and stepwise transfer). Worked for us recently when 0.2M sodium malonate was competing out the ligand (which is ironic given that sodium malonate would be my first choice of replacing ammonium sulfate when it is major precipitant, see Holyoak et al., Acta Cryst D59:2356).
HTH, Ed. On Fri, 2010-04-23 at 12:53 -0500, Yi-Liang Liu wrote: > Hi Everyone, > > I have a question about the crystallization condition. Currently the > condition I use contains 0.2M lithium sulfate. However, the ligand > there seems to compete the site where sulfate binds in the active > site. Are there any good substitute to replace the Lithium sulfate in > my crystallization buffer? > > > Best, > > > Lucas > > > -- Edwin Pozharski, PhD, Assistant Professor University of Maryland, Baltimore ---------------------------------------------- When the Way is forgotten duty and justice appear; Then knowledge and wisdom are born along with hypocrisy. When harmonious relationships dissolve then respect and devotion arise; When a nation falls to chaos then loyalty and patriotism are born. ------------------------------ / Lao Tse /
