[3dem] Contamination problem on cryo grids

[Bill Tivol]

On Sep 19, 2008, at 4:41 AM, Anselm Kusser wrote:

>
>> We are repeatedly experiencing problems with significant amount of  
>> contamination on our grids (follow the links to have a look at some  
>> example images).

> What you are seeing is not contamination, it is what we term  
> "splotchy ice" which occurs if there are contaminants on the carbon  
> causing the carbon to be hydrophobis not hydrophyllic.


Dear Anselm,
	Another possibility is that there is a contaminant in the ethane.  We  
sometimes see this when the ethane tank is nearly empty.
Yours,
Bill Tivol, PhD
EM Scientist
Ultrafast EM Facility
Noyes Laboratory, MC 127-72
California Institute of Technology
Pasadena CA 91125
(626) 395-8833
tivol at caltech.edu