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

[Sjors Scheres]

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
>>
>>
>> _______________________________________________
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> --
> 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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-- 
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