Accession Number : ADA308381

Title :   Development and Application of Low-Temperature AFM.

Descriptive Note : Final rept. 1 Oct-31 Dec 95,

Corporate Author : VERMONT UNIV BURLINGTON DEPT OF PHYSICS

Personal Author(s) : Yang, Jie

PDF Url : ADA308381

Report Date : 30 JAN 1996

Pagination or Media Count : 9

Abstract : With the support from the US Army Research Office, we have continued our efforts in biological applications of atomic force microscopy. Our instrumentation development, based on what we have achieved with a prototype low temperature atomic force microscope, will allow us to conduct structural studies under a controlled temperature over a wide range. We have developed various methods to facilitate atomic force microscopy of biological specimens at room temperature. Preparing supported bilayers made of cationic lipids enabled us to image DNA molecules in solution at a resolution high enough to resolve the pitch of DNA. We also discovered that membrane-bound DNA molecules are closely packed. Using mica chips as substrates allows us to study thermal properties of supported bilayers with a differential scanning calorimeter. Our results show that there is a new high-temperature phase in supported phospholipid membranes. We have recently developed a method to use a protein label to study the process of how a hydrophobic entity inserts into a supported bilayer. This will help us to understand the insertion process which is essential for the understanding of the function of many integral membrane proteins.

Descriptors :   *LOW TEMPERATURE, *DEOXYRIBONUCLEIC ACIDS, *ELECTRON MICROSCOPY, SCANNING, THERMAL PROPERTIES, CATIONS, ARMY RESEARCH, BIOLOGY, MOLECULES, STRUCTURAL PROPERTIES, HIGH TEMPERATURE, LIPIDS, PROTEINS, ELECTRON MICROSCOPES, CHIPS(ELECTRONICS), SUBSTRATES, ROOM TEMPERATURE, IMAGES, INSTRUMENTATION, MEMBRANES, TEMPERATURE CONTROL, RANGE(EXTREMES), CALORIMETERS, PHOSPHOLIPIDS, MICA.

Subject Categories : Biochemistry
      Test Facilities, Equipment and Methods
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE