Automated CCD Data Collection and 3D Reconstruction of Aleutian Mink Disease Parvovirus

Abstract

Acquisition of CCD image data from frozen-hydrated specimens provides several advantages compared with the use of photographic film. CCD cameras possess excellent linearity, sensitivity and dynamic range. The CCD also allows one to pre-check the quality of a cryo sample much easier than with a TV rate camera or on film. However, the limited field of view (IK2 pixels) of the CCD makes data collection difficult. Gatan, Inc. has produced a LowDose software package, in conjunction with their DigitalMicrograph™ environment, that automates this process and allows for efficient collection of larger amounts of data. This software, along with our own image analysis software, has facilitated the computation of a three-dimensional reconstruction (3D) from images of baculo-expressed, VP2 particles of Aleutian mink disease parvovirus (ADV).ADV has a capsid (∼28.5 nm diam.) that contains two proteins (VP1-2) of which ∼90% is VP2. ADV infections lead to plasmacytosis in mink and are a significant problem worldwide.