Accession Number : ADA291704

Title :   Development and Application of Low-Temperature AFM.

Descriptive Note : Final rept. 1 Nov 91-31 Oct 94,

Corporate Author : VIRGINIA UNIV CHARLOTTESVILLE

Personal Author(s) : Yang, Jie ; Shao, Zhifeng

PDF Url : ADA291704

Report Date : 30 JAN 1995

Pagination or Media Count : 19

Abstract : With the support from the US Army Research Office, we have established the basis of using state-of-the-art atomic force microscope (AFM) to image biological specimens at sub-nm resolution at cryogenic temperatures under ambient pressure. Our instrumentation demonstrated convincingly that a contamination environment can be obtained as we proposed originally, and the performance of our prototype AFM at cryogenic temperatures was at least comparable to, if not better than, any atomic force microscope available today. We have also developed various methods to facilitate atomic force microscopy of biological specimens at room temperature. Modification of the Kleinschmidt methods enabled us to image DNA specimens in air at a resolution of 4-6 nm. Reliable preparation of supported bilayers enabled us to study the structure of lipid bilayers in situ, leading to the elucidation of interesting phenomena which are impossible to reveal by other available methods, and the imaging of membrane proteins in physiological conditions at a resolution of 1 nm. We also developed methods to image soluble proteins in solution at a resolution of 1 nm. These suggest strongly the usefulness of AFM in biology that it can be used to solve problems which are difficult to tackle with other methods.

Descriptors :   *LOW TEMPERATURE, *PHYSIOLOGICAL EFFECTS, ENVIRONMENTS, ARMY RESEARCH, PREPARATION, BIOLOGY, LAYERS, LIPIDS, PROTEINS, DEOXYRIBONUCLEIC ACIDS, ROOM TEMPERATURE, RELIABILITY, IMAGES, PRESSURE, MEMBRANES, CONTAMINATION, SOLUBILITY, MICROSCOPES, CRYOGENICS.

Subject Categories : Medicine and Medical Research
      Atmospheric Physics
      Medical Facilities, Equipment and Supplies

Distribution Statement : APPROVED FOR PUBLIC RELEASE