[3dem] Quality of ethane for freezing

[Cindi Schwartz]

To Ariane's point, we also use the ethane/propane mix with great success, but I confess we just use the propane you can buy at the hardware store. I'm feeling like our grids look fine. We use the highest purity ethane we can find, though.

Cindi


On Feb 1, 2013, at 9:55 AM, Ariane Briegel wrote:

> Dear Esther, 
> we had similar issues a few years back. If I remember correctly,the "pure CP Ethane" label of the ethane changed to  99%  purity, whereas older "pure CP Ethane" was specified  99.5%.
> After we ordered a higher grade ethane, there contamination issues disappeared.
> 
> We also use an ethane/propane mix in the lab- this mixture doesn't freeze at all and we have great success using it:
> An improved cryogen for plunge freezing. Microscopy and Microanalysis : the Official Journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada, 14(5), 375–379. 
> Good luck!
> 
> 
> ––––––––––––––––––––––––––––
> Ariane Briegel, Ph.D.
> California Institute of Technology
> Broad Center, MC 114-96
> 1200 E. California Blvd.
> Pasadena, CA 91125
> 
> Tel: 626-395-8848
> Fax: 626-395-5730
> ––––––––––––––––––––––––––––
> 
> 
> 
> On Feb 1, 2013, at 8:22 AM, Bullitt Esther wrote:
> 
>> Hi,
>> 
>> We have always bought technical grade ethane rather than the high purity.  By the bottom of the tank, the grids have contamination, and so we switch it out.
>> 
>> This last time, the tank cost half the price, and has been showing contamination pretty soon after we started using it.  Perhaps it is now a lower grade.
>> 
>> Do people recommend buying the high purity ethane?  My understanding is that it then freezes very rapidly, so one must contend with thawing it often.
>> 
>> thanks,
>> Esther
>> 
>> ---
>> Esther Bullitt, Ph.D.
>> Dept. of Physiology & Biophysics
>> Boston University School of Medicine
>> 700 Albany Street, Room W302
>> Boston, MA  02118-2526
>> 
>> Email:      bullitt at bu.edu
>> Telephone:  617-638-5037
>> Facsimile:  617-638-4041
>> http://www.bumc.bu.edu/phys-biophys/faculty/bullitt
>> 
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> 
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****************************
Cindi L. Schwartz
University of Colorado
Dept. MCDB
347 UCB
Boulder, CO  80309
O: 303-492-7980
F: 303-735-0770
http://bio3d.colorado.edu
****************************

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