Forum 11/30/2006

“Camera Possibilities for EM and Cryo-EM of Biological Specimens:  More pixels, better pixels or both?”

Paul Mooney – Gatan, Inc.

Many development pathways are opening up for improving image capture for biological EM.  These include larger sensor areas, higher pixel rates and improved energy conversion technologies for better sensitivity and resolution.  It remains unclear what approach or combination of approaches will yield needed improvements.  It is also unclear what metrics to use when making tradeoffs.  The main difficulty lies in the unclear link between technical descriptors of camera and raw image quality (e.g. detective quantum efficiency, spectral signal to noise ratio) and the sought-after fidelity to biological structure.  A further complication is created by systems issues such as microscope hysteresis and grid hole size which, while not involving imaging acquisition per se, indirectly determine image acquisition strategy through their influence on specimen and imaging condition stability.  This talk will attempt not to answer but to point the way towards how to answer the question in the title.  Some metrics will be proposed and some current camera possibilities will be compared in terms of those metrics.  The appropriate combination of camera size, speed and sensitivity depends strongly on the application and the answer will ultimately have to come from the community of users.  There will be a chance for open discussion.  Feedback will be strongly encouraged.