IMAGING, SPECTROSCOPY AND TOMOGRAPHY OF FROZEN HYDRATED SPECIMENS WITH THE CRYO SCANNING TRANSMISSION X-RAY MICROSCOPE AT THE NSLS

With the steady improvement of x-ray optics with high resolution and efficiency, and continued development or adaptation of different imaging and measuring techniques, soft x-ray microscopy has emerged as a powerful method to image and analyze fully hydrated specimens of several micrometer thickness at sub-optical resolution (for a recent overview, see ref. 1). We report on experiments performed with the cryo scanning transmission x-ray microscope (cryo-STXM), which has recently come into operation at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. Cryo-STXM uses x-rays with energies between the absorption edge of Carbon (E = 284 eV) and Oxygen (E = 543 eV) from the soft x-ray undulator at the NSLS. Fully hydrated specimens such as eucaryotic cells in water or ice layers of up to 10 micrometer thickness can be imaged without any additional need for contrast enhancing techniques.