... CrystalScreen I by Hampton Research. Optimization of the molec-ular weight of poly(ethylene glycol) and its concentration,together with pH, led us to the final crystallization condi-tion of 7.5% poly(ethylene ... round of refinement were R = 26.7% and Rfree= 34.9%. When atwin operator was included, R-value and Rfree-value weredecreased to 19.2% and 25.2%, respectively. Refinement of the model and twin ... Kruus2,Juha Rouvinen1 and Nina Hakulinen11 Department of Chemistry, University of Eastern Finland, Joensuu, Finland2 VTT Technical Research Centre of Finland, Espoo, FinlandKeywordsascomycete;...