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
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
