Abstract

We describe the use of intense pulsed (<1 ns) x- rays from a laser-plasma for making highresolution (100 Å), high-contrast, contact images of hydrated human chromosome fibers. The fibers are suspended in a 10 μm thick H₂O cell having a thin 100 nm SiN entrance window anda rear recording panel of PMMA resist. Single-shot irradiation of the cell with x-rays generated from an Au laser-plasma produced by a 5 J, 1 ns duration, laser pulse at 526 nm is sufficient to expose the resist for a cell-target separation of 20 mm. The detailed structure of the image created in three-dimensional relief in the PMMA is faithfully transferred to a thin, positive polymer replica and analyzed with high-resolution electron microscopy. We discuss the implications of this work and describe refinements to this approach that will enhance its usefulness in highresolution imaging of in vitro specimens in the biological and life sciences.

© 1992 Optical Society of America