[3dem] electron dose & data collection strategy for Titan Krios, 300kV, Falcon back thinned

[Joachim Frank]

Dear Max:

That beginning exposures experience more drift, until the sample 
settles, has been observed in electron tomography for years.

--Joachim.

On 1/14/2014 5:58 AM, Sjors Scheres wrote:
> Hi Max,
> Xueming Li, Yifan Cheng et al. describe in Nature Methods (2013) that 
> "motion was fast in the beginning of the exposure and that it slowed 
> down quickly (Fig. 3c 
> <http://www.nature.com/nmeth/journal/v10/n6/full/nmeth.2472.html#f3>)", which 
> could explain the observation that the first few frames are worse. Why 
> the particles would move faster in the beginning is not clear (at 
> least to me).
> HTH, S
>
>
> On 01/14/2014 10:35 AM, m.maletta at nki.nl wrote:
>> Dear Sjors,
>> I never heard about kicking out the fist two frames. Do you have any 
>> idea why is so?
>> It is somewhat related to the charge-peeling of the exposure area?
>> Best
>> Max
>> __________________________________
>> Massimiliano Maletta
>> post-doc in
>> NKI Netherlands Cancer Institute -Antoni van Leeuwenhoek Hospital 
>> Plesmanlaan 121 B6 1066CX Amsterdam
>> group of Peter Peters
>> www.nki.nl/research/peters/   | www.necen.nl
>> m.maletta at nki.nl
>> Tel : +31 20 512 2022
>> Fax : +31 20 512 2029
>> ________________________________________
>> From: 3dem-bounces at ncmir.ucsd.edu [3dem-bounces at ncmir.ucsd.edu] On 
>> Behalf Of Sjors Scheres [scheres at mrc-lmb.cam.ac.uk]
>> Sent: Tuesday, 14 January 2014 11:08 AM
>> To: 3dem at ncmir.ucsd.edu
>> Subject: Re: [3dem] electron dose & data collection strategy for 
>> Titan Krios, 300kV, Falcon back thinned
>>
>> One other observation that may be relevant to your experiment: with the
>> settings just described, the first 1-2 movie frames (out of a total of
>> 17 for the 1s exposure) are often significantly worse than frame 3. If
>> you will be limited by FEI's 7-frame capturing system, you may want to
>> skip the first 1 or 2 frames.
>> HTH, S
>>
>>
>>
>> On 01/13/2014 03:50 PM, Shabih Shakeel wrote:
>>> Dear All,
>>>
>>> I am going to collect single particle data on Titan Krios operated at
>>> 300kV with Falcon II (back-thinned) detector. The sample is
>>> icosahedral virus of 30nm diameter. Does any one have experience
>>> collecting data in these settings?
>>>
>>> We are especially looking for comments or advice on electron dosage to
>>> use and number of frames to record with an aimed resolution of 3-5Å.
>>> This is our one shot at collecting the data for this sample, so we
>>> really want it to work.
>>>
>>> Of course, any other useful comments, advice, tips would also be
>>> appreciated.
>>>
>>> Thanks a lot.
>>>
>>> Best Regards,
>>> Shabih Shakeel
>>>
>>>
>>> ---------------------------------------------
>>> Shabih Shakeel, MSc
>>> Doctoral researcher
>>> Butcher group
>>> Institute of Biotechnology
>>> P.O. Box 65 (Viikinkaari 1)
>>> 00014 University of Helsinki
>>> Finland
>>>
>>> cell: +358 46 8430774
>>>
>>>
>>> _______________________________________________
>>> 3dem mailing list
>>> 3dem at ncmir.ucsd.edu
>>> https://mail.ncmir.ucsd.edu/mailman/listinfo/3dem
>> -- 
>> Sjors Scheres
>> MRC Laboratory of Molecular Biology
>> Francis Crick Avenue, Cambridge Biomedical Campus
>> Cambridge CB2 0QH, U.K.
>> tel: +44 (0)1223 267061
>> http://www2.mrc-lmb.cam.ac.uk/groups/scheres
>>
>> _______________________________________________
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>

-- 
Joachim Frank, Ph.D.
Howard Hughes Medical Institute Investigator,
Professor, Department of Biochemistry and Molecular Biophysics,
and Department of Biology, Columbia University,
650 W. 168th Street, P&S Black Building 2-221
New York, NY 10032
(T) 212 305-9510  (Masgan Saidi, admin. assistant 212 305-9512)
(F) 212 305-9500
(E) jf2192 at columbia.edu
http://franklab.cpmc.columbia.edu
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http://www.fi.edu/franklinawards