Three-dimensional visualization in projection X-ray microscopy of biological specimens

Abstract
We have developed a projection X-ray microscope by modifying a conventional scanning electron microscope (SEM). The operational process for optical alignment and focusing is as simple as with SEM. Because there are no X ray optical elements (e.g. a zone plate), this microscope can achieve a fairly deep focal depth. This implies it is possible to obtain projection images of thick and opaque sample in a single image without having to construct a composite image from thin sections. Taking this advantage. we inspected internal structure of thick biological specimens that were impossible to observe directly by either optical or electron microscopy.