Tb-Xo4 is a complementary product and not a substitute for commercial crystallization kits. It should be used as an additive in screening kits and therefore fits with current end users practices. In order to get as many exploitable hits as possible, the optimal crystallization experiment would combine screening of conditions of the protein both in native conditions and in the presence of Tb-Xo4 (i.e. : two drops should be made, with and without 10 mM Tb-Xo4).
Tb-Xo4 is fully compatible with conventional phasing methods. Prior to data collection, carry out a rapid (from 30 sec to 5 min) soak of crystals in a concentrated Tb-Xo4 solution (100mM) in mother liquor supplemented with a cryo-protectant. To fully exploit the anomalous contribution of Terbium, an X-ray fluorescence scan can be performed to precisely define the peak and the inflection wavelengths of the Tb LIII absorption peak and to set the energy of the X-ray beam.