Dear all, I am sorry for this off topic question in the bb. I have good looking but poorly diffracting (3.8-4 A) crystals of SeMet derivative. Mass spec confirmed that Se incorporation is 100% and I got a very good energy scan for Se too. I properly selected the peak, inflection and remote wavelengths for the data collection. But, I do not see anomalous signal in the data collected. Processing in HKL2000 does not show any resolution dependance of Chi square and also xtriage says that the anomalous resolution limit is only up to 8-9A. Is it something usual for the kind of diffraction I am getting or something else is going on? I have 5/200 methionine residues in the sequence. Worst case I can think of is that all the Met side chains are disordered ! Any help would be highly appreciated.. AK