XP Up Screen

The additive TEW has proven to promote crystal contacts, improve crystal quality and further provides a valuable anomalous signal for phasing due to 6 tungsten atoms[1]. It has successfully induced protein crystallization at low concentrations such as 1 mM[2,3]. However, own experiments revealed that a higher concentration of 5 or 10 mM TEW can significantly increase crystallizability once again. The XP Up Screen provides 96 of the most prominent crystallization conditions that have proven to be successfully upgraded with up to 10 mM TEW. To offer full flexibility in terms of final concentration, TEW is provided in an extra tube to be added to the protein droplet only. The 96 screening solutions are long-term stable also in the presence of up to 10 mM TEW allowing maximum flexibility with no compromise.