[3DEM] Quantifoil hole sizes off?

[Bob Grassucci]

Hi Prabha,
         We have also run into this situation.  The hole sizes are usually 
consistent within a batch and the distance between holes is generally 
consistent.  I suspect that the problem comes from the amount of time the 
grids are treated to form the holes.  When we make holey grids this 
treatment is with acetone and if necessary heat to pop pseudo holes before 
floating off the holey plastic and then carbon coating the grids.  I am not 
certain, but I suspect there is probably a similar approach with the 
Quantafoil grids.  It is just a matter of quality control and timing.  If 
it is a problem I would contact the vendor directly and ask for a 
replacement batch of grids.  Good luck
         Bob

At 05:44 PM 2/23/04 -0800, D. Prabha Dias, PhD wrote:
>**** Messages to this list are automatically archived ***
>**** Please limit quoting of previous postings to the bare minimum ****
>
>Hello all-
>  We've found that recent batches of Quantifoil grids have hole sizes that 
> are significantly larger than the specifications.  We're using 200 mesh 
> Cu/Rh grids with either R2/2 foil or R1.2/1.3 foil, carbon-coated at the 
> factory.  The most recent batch of R2/2 appears to have holes that are 
> approximately 2.7-2.8 microns in size, while the R1.2/1.3 foil appear to 
> actually have ~1.9 - 2.2 micron holes. Has anyone else had similar 
> experiences?  Thank you for your time & attention.
>
>-Prabha
>
>--
>D. Prabha Dias, Ph.D.
>E.M. Scientist, Jensen Lab
>Division of Biology
>California Institute of Technology
>M/C 114-96
>1200 East California Blvd.
>Pasadena, CA 91125
>
>phone: (626)395-8829
>fax: (626)395-5730
>email: prabha at caltech.edu
>
>
>--
>For information on how to subscribe/unsubscribe/etc., send mail to
>3dem-request at 3dem.ucsd.edu with the text "help" in the body of the
>message.

Robert Grassucci
Howard Hughes Medical Institute at The Wadsworth Center
Empire State Plaza
Albany, NY 12201-0509
Phone: (518)474-5821
Fax: (518)486-2191
E-Mail: bobg at wadsworth.org