X-ray Diffraction Recording from a Small Amount of Fibrous Protein Materials Oriented by a Micro Shear-Flow Cell

This paper describes a method for recording X-ray diffraction patterns from a small amount of fibrous protein materials while being oriented by using a micro shear-flow cell. This cell consists of two concentrically arranged glass tubes. The inner tube is stationary, while the outer one rotates at a high speed. The gap between the two tubes is about 100 μm, into which the suspension of fibrous protein materials is injected. By using synchrotron-radiation X-ray microbeams (diameter, 10 μm), clear diffraction images from oriented protein materials can be recorded. The required volume of the sample is only about 10 μl. This method can also be combined with the laser-flash photolysis of caged compounds. Examples of application of this method to the flagella of a green alga Chlamydomonas, and sperm of a tunicate Ciona are presented.