Use the scan.
And yes, don't fry your crystal doing it. The best way to do this is put
the fluorescence detector as close to the sample as you can and then
optimize the count rate by attenuating the beam. However, some beamlines
are set up to hit your crystal with full beam and then back off t
12:16 PM
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] MAD wavelength
Dear All:
Next week we are going to try some seleno-Met labeled crystals.
We checked the literature to try to find out the peak wavelength
that has been used for SAD or MAD data collection. But they are slightly
dif
On a different note,it seems as if SeMet is not a regular experiment
in your lab. So I would recommend not to burn your crystals and rather
sacrifice the resolution versus loosing your SeMet anomalous signal
after couple of degrees into the data collection. It would also be
wise to run Mosf
On Thursday 16 July 2009 10:15:51 Jerry McCully wrote:
>
> Dear All:
>
> Next week we are going to try some seleno-Met labeled crystals.
>
> We checked the literature to try to find out the peak wavelength that
> has been used for SAD or MAD data collection. But they are slightly diff
I second Phil's opinion - it is better to scan and be sure - as long as
the scan results are not hideously abnormal. If you cannot scan for
whatever reason but are sure that the X-ray optical system is properly
calibrated - then use Phil's numbers below :)
Artem
> Always take the scan results ahe
Just checking my oxidized Se-Met experiments, I have 12658 to 12661 eV
for my peak energies, and 3 eV lower for the inflection.
As others have said, do the fluorescence scan. Use your experimentally
determined values.
Engin
On 7/16/09 11:54 AM, Phil Jeffrey wrote:
Always take the scan results
Always take the scan results ahead of the typical values unless they are
obviously wrong. Only use the "predicted" values if the scan is broken
or too weak (e.g. very small crystals) and in that case I'd be tempted
to add 10-20 eV to the "typical" peak wavelength to make sure you
weren't actua
To: CCP4BB@JISCMAIL.AC.UK
Sent: Thursday, July 16, 2009 12:15 PM
Subject: [ccp4bb] MAD wavelength
Dear All:
Next week we are going to try some seleno-Met labeled crystals.
We checked the literature to try to find out the peak wavelength that
has been used for SAD or MAD data colle
Dear All:
Next week we are going to try some seleno-Met labeled crystals.
We checked the literature to try to find out the peak wavelength that has
been used for SAD or MAD data collection. But they are slightly different ( may
be 50 ev) in different papers.
I guess this is due
