Analytical Sciences

Abstract − Analytical Sciences, 28(1), 65 (2012).

X-ray Diffraction of Protein Crystal Grown in a Nano-liter Scale Droplet in a Microchannel and Evaluation of Its Applicability
Masatoshi MAEKI,*1 Saori YOSHIZUKA,*1 Hiroshi YAMAGUCHI,*2 Masahide KAWAMOTO,*3 Kenichi YAMASHITA,*2 Hiroyuki NAKAMURA,*2 Masaya MIYAZAKI,*1,*2 and Hideaki MAEDA*1,*2,*4
*1 Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-Koen, Kasuga, Fukuoka 816–8580, Japan
*2 Measurement Solution Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 807-1 Shuku, Tosu, Saga 841–0052, Japan
*3 Kyushu Synchrotron Light Research Center, 8-7 Yayoigaoka, Tosu, Saga 841–0051, Japan
*4 CREST, JST, 5 Sanban-cho, Chiyoda, Tokyo 102–0075, Japan
We describe the technical aspects of the in-situ X-ray diffraction of a protein crystal prepared by a nanodroplet-based crystallization method. We were able to obtain diffraction patterns from a crystal grown in a capillary without any manipulation. Especially in our experimental approach, the crystals that moved to the nanodroplet interface were fixed strongly enough to carry out X-ray diffraction measurements that could be attributed to the high surface tension of the nanodroplet. The crystal was damaged by an indirect action of the X-rays because our in-situ X-ray diffraction measurement was carried out in the liquid phase without freezing the crystal; however, the obtained several diffraction patterns were of sufficiently fine quality for the crystal structure factors to be generated. We consider the technical examination presented in this paper to represent a seamless coupling of crystallization to X-ray analysis.