[3dem] Thinner ice after several microscope uses

[Eduardo Sanz Garcia]

I was analyzing the success rates of my cryoEM sessions and I noticed a 
trend: When I am the first microscope user of the day I always have 
thick ice and the chances to obtain better ice improve after several 
consecutive trials.

First user of the microscope (No previous users before me)

	Number of days with good ice
	Number of days with thick ice
First trial
	*0*
	*11*
Second trial
	5
	3
Third
	1
	1


It could be either:

    * I don't pre-cool well the cryoholder and the first use is not
      totally ready (I cool off the holder inside the microscope, and it
      is always at -180 C)
    * Microscope related issues (the vacuum is better after sometime,
      *we start a cryocycle every night*).


I believe that it is a microscope related issue because, when I used the 
microscope after another user I get better chances to obtain thin ice:

*After* another microscope user

	Number of days with good ice
	Number of days with thick ice
First trial
	7
	3



Have anyone noticed a similar trend?

Additionally, I would like to ask you how consistent your sample 
preparation are.
I always prepare the samples in the same way, and I get very 
inconsistent results, sometimes thick ice, sometimes thin ice,
If you prepare several sample under the same conditions (vitrobot, 
handling, etc...) , do you obtain

    * 100% consistent results
    * 80-90% consistent results
    * less than 50% consistent results?

Thank you very much.

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