I have wondered if placing a layer of oil over the drop would help solve the problem of the crystals moving around. Haven't tried it, but don't people harvest from a microbatch tray by dragging the loop and crystal through oil?
Nat On Fri, Apr 9, 2010 at 11:21 AM, James Holton <jmhol...@lbl.gov> wrote: > Yes, isopropanol is a cryoprotectant, and a relatively good one. So are the > other alcohols. It was even popular in the "olden days" when we would > typically set up drops that were 5-10 microliters in volume (each!). These > take a while (minutes) to evaporate, giving you enough working time to mount > the crystal before the alcohol concentration changed "too much". Modern > nanoliter-scale drops have largely made alcohol additives impractical, which > is a shame. > > A potentially general way to deal with evaporating drops is to bathe the > work area in a stream of air or nitrogen that has been pre-saturated with > the reservoir solution. That is, run the gas line in and out of a jar of > say about 50-100 mL of replicated reservoir solution (bubbling the gas > through the solution in the jar) and then route the end of the hose to under > your dissecting microscope and point it at your crystallization well just > before you crack it open. This should give you a nice, long working time, > and similar devices have already been reported in the literature: > > http://dx.doi.org/10.1107/S0021889801020702 > > That, or you can try to just work really quickly! > > -James Holton > MAD Scientist > > Chris Meier wrote: >> >> Dear all, >> >> I have a protein which crystallizes in 25% isopropanol, at pH4.5. >> >> Does anyone have experience freezing crystals grown in such a condition? >> What cryoprotectants should I try? Can isopropanol itself act as a >> cryoprotectant? Any suggestions on how to deal with isopropanol evaporation >> during mounting? >> >> Many thanks and best wishes, >> Chris >> >> >> >
