Microscope

Mikroskop

The Leica DMLA microscope with a CCD camera

 

microscope:

  • Leica DMLA
  • C-mount/F-mount/0.5x TV optics 0.5x for CCD camera
  • 10x eyepiece, binocular phototube with photoprism for beam separation
  • motorised, electronically steerable 6x objective revolver
  • air objectives 5x/0.15, 10x/0.30, 20x/0.70, 40x/0.75
  • oil immersion objectives 63x/1.32, 100x/1.35
  • motorised, electronically steerable focus drive, resolution 0.015µm
  • motorised, electronically steerable x/y stage, resolution 0.3µm
  • external control gear, PC interface RS 232C
  • comprehensive software developer’s kit (SDK)
  • ergonomic x/y/z manual control element

camera:

  • JAI CV-M90
  • 3-CCD, 1/3″
  • resolution 752×582 pixels
  • pixel size 6.50µm x 6.25µm (at PAL)
  • shutter speeds 1/60sec – 1/10000sec
  • electronically steerable (e.g. shutter speed , RGB gain)

PC system:

  • Intel Pentium architecture
  • RAID drives
  • dual head graphics card for simultaneous display of the live image on a second screen
  • frame grabber
  • data exchange with database and RAID image archiving system over 1 GBit network

The microscopy hardware employed at the LfB lays the foundation for the development of a forward-looking digital microscopy workstation.
The Leica DMLA is equipped with corrected objectives for high imgage contrast and a sharp, hardly distorted, chromatically corrected image.
The light source, powered by a stabilised power source, facilitates a constant, hardly jitter-affected illumination of the field-of-view.
A 3-CCD camera with large detector elements keeps the loss of quality during the image capture process marginal.

All components were assembled with a particular focus on automatability.
So the Leica DMLA holds functionality for fast, reproducible positioning of the x/y stage, adjustment of the focal plane (autofocus, with problem-adapted algorithms from the LfB), and change of objective for capturing at a varying field of view. Camera parameters, such as channel-dependent gain or shutter speed,
can be electronically steered as well. This enables, for instance, automatic white balancing or high dynamic range imaging (HDR).

Highly automated future image analysis systems, too, require intuitive and transparent user interfaces. Thus the microscope’s external manual conrol element,
with which one can alter x/y position, focus and objective one-handedly, and the simultaneous display of the camera’s live image and an application on two screens
provide the basis of an ergonomic and efficient work flow.

One application example of the microscopy workstation is the multimodal cell analysis (MMCA), for which a cell preparation from cytopathological cancer
diagnostics is first stained by one of a set of several different stains. Then cell images are captured and analysed computer-assisted. When a first stain does not allow for an unambiguous diagnosis, the preparation is (if necessary multiply) de- and restained so that other cell features become visible, and the capture
and analysis process is repeated. The key feature is that cells stick to their positions, and with the help of the x/y stage’s positions from the previous capture
session, which are stored in a database, images of identical cells are obtained. Thus one acquires for each cell a step by step extending vector of diagnostic
measurements that combines the analyses synergetically.