Biospec. The chamber caps are dimpled, so when they are tightened, they displace air and a bit of liquid out the top of the chamber. The amount of remaining air is very very small if done properly. The chamber should be completely full of liquid to work as intended.
Roger Rowlett On Oct 26, 2012 1:30 AM, "Dima Klenchin" <klenc...@facstaff.wisc.edu> wrote: > Roger Rowlett wrote: > > No air in the vessel, no foam. >> > > What manufacturer/model do you use? I can't quite imagine a beater that > would have no air in the chamber but maybe there is something new under the > sun. > > Yield of soluble, active protein from broken cells is quite comparable or >> better than French press or sonication, but with no aerosols. The >> bead-beating unit is encased in ice water, and is used 15 s on and 45 sec >> off to minimize heat buildup. The solution still feels cold when >> transferred to centrifuge tubes for clarification. I suppose I could >> measure it next time to see how much it actually warms up during beating. >> >> Based on these observations, I conclude that the cell lysis by >> bead-beating is no more disruptive to proteins than a French press, but >> much, much faster. As a bonus, genomic DNA is sheared, so no more slimy >> lysates. We have used bead beaters exclusively since 1997 or so when I >> learned about them from a Swedish research group I was visiting. They are >> handy in both the teaching and research lab. >> > > Interesting. I've never used bead beaters for E.coli work and only used it > once with yeasts. What I saw went well with what I read in the past from > others: > http://www.bio.net/bionet/mm/**methods/1994-May/014416.html<http://www.bio.net/bionet/mm/methods/1994-May/014416.html> > Quote: "A comparison of sonication and beating showed that beating was > much harsher FOR OUR HEAT-LABILE ENZYME IN THE PLASTIC CUP than sonication". > > Metal chamber is surely going to help but foaming is still a concern in my > mind. > > - Dima > >
