From: Virgil R. Schirf <schirfv@bioc09.v19.uthscsa.edu>
  To  : rasmb@bbri.org <rasmb@bbri.org>
  Date: Tue, 29 Aug 2000 10:06:47 -0500

Re: scratches on centerpieces

You can use the round, gel loading tip with 1000 ul pipettors by
piggybacking the gel loading tip onto the 1000 ul tip. In that way you
can load at one time which avoids other problems especially when working
with detergents, etc.

Virgil Schirf
Center for the Analytical Ultracentrifugation of Macromolecular
Assemblies
Department of Biochemistry
The University of Texas Health Science Center at San Antonio
email schirfv@biochem.uthscsa.edu
phone (210) 567-6590

"Disher, Rose [CNTUS]" wrote:
> 
> This may be old news to many of you, but I thought I would share this
> anyway.  We do lots of SDS-PAGE in our group, and have thin pipet tips used
> for loading gels around the lab.  I have found that a round-tip gel loading
> pipet tip on a 200mL pipettor works really well for loading sedimentation
> velocity cells and is much less expensive than the Leur-Lok Hamiliton tubing
> recommended by Beckman.  It also prevents the operator from accidentally
> stabbing the centerpiece or him/herself with a syringe needle. Although
> using the tips requires two pipettings to fill a standard cell, this also
> has the advantage of eliminating the risk of cross contamination that comes
> with the syringe/tubing method.  Another benefit is the additional reduction
> in the usually low risk of the accidental introduction of metal ions from a
> syringe needle into the sample.  The low level of metal ions from a needle
> is usually not a real problem, but could be an additional source of
> artifacts for someone looking at proteins with metal-sensitive conformations
> (eg. ion channels, heme proteins, zinc finger regions, etc.)
> 
>