I've found the scala CC-anom significantly underestimates the anomalous
signal, relative to e.g. xprep. I don't know why that is, but the
latter seems to agree with what shelxd is happy with.
Cheers
phx
On 29/06/2010 10:35, Graeme Winter wrote:
> Hi Murugan,
>
> One useful indicator of raw anomalous signal is the ANOMPLOT graph
> from Scala - this shows the differences between reflections compared
> with the expected differences. If the gradient of the plot is 1
> there's no more differences that you would expect. If the gradient is
> more than one there is (or may be.) - also check out the merging
> statistics as a function of batch, if there's significant radiation
> damage this may mess things up.
>
> Scala writes out the gradient (assuming you told it anomalous on) in the summary
>
> Another rule-of-thumb is the resolution limit where cc-anom is> 0.5.
>
> The most practical indicator of the anomalous signal is of course the
> success or failure of the subsequent phasing :o)
>
> Best wishes,
>
> Graeme
>
> On 29 June 2010 10:05, Vandu Murugan<[log in to unmask]> wrote:
>
>> Dear all,
>> I have collected a 2.7 angstrom home source data with Cu-Kalpha source
>> for a protein with 6 cysteines, with a multiplicity of around 23. I need to
>> know, is there any significant anamolous signal present in the data set,
>> since there is no good model for my protein. Can any one tell, which
>> program to run, and what parameter to see? Thanks in advance.
>>
>> cheers,
>> Murugan
>>
>>
|