[3dem] tilt cryoEM goniometer before sample holder insertion

[Jacob Brink]

Dear Jim,

Yes, you can do this also with the older 2010Fs. But, there's no need to pre-tilt the gonio that far. Typically, I would pre-tilt the gonio to 10 or 15 degrees, insert the cryoholder and start the pumping sequence. Once I get a green light, I grab the cryoholder and turn the stage back to zero tilt thus in one motion making the required 10 degrees rotation to get the holder past the micro-switches. Then one can proceed with the remainder of the insertion.

This of course required that one does not fill the cryo-holder that much. Try to keep the level of liquid nitrogen below the central rod. That gives you enough cryogen  to keep the sample cold during the transfer without any spill.

Good luck.

Jaap (JEOL USA).

On Apr 2, 2011, at 10:36 PM, Jingchuan Sun wrote:

> Hello,
> Before cryoEM sample holder insertion, it is rotated 90 degree, so most liquid N2 is poured toward user from dewar. I heard that new TEM goniometer could be tilted before holder insertion. Anyone try it with older TEM?
> 
> I'm thinking two ways for our JEOL2010F.
> 1) tilt gonimeter +60 degree, insert sample holder (dewar is -30 degree), flip airlock switch to "PUMP", after green light is on and wait for another ~5 min, turn the holder clockwise ~30 degree (now dewar is straight up), tilt gonimeter back to +30 degree, then turn the holder clockwise another ~60 degree (now dewar is +30 degree right), and finally tilt gonimeter back to 0 degree (now dewar is straight up).
> 
> 2) tilt gonimeter +45 degree, insert sample (now dewar is -45 degreet), flip airlock to "PUMP", after greenlight is on and wait for ~5 min, turn the holder ~30 degree (now dewar is -15 degree left) and another ~60 degree (now dewar is -45 degree), finally tilt gonimeter back to 0 degree.
> 
> The first method need tilt gonimeter two times at high angle, but the holder's dewar is only rotated within 30 degree. 
> 
> Anyone try it on JEOL2010F? If it works, it reduce one hazardous operation in cryoEM. 
> Thanks!
> Jim
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