Using a modified standard microscope to generate virtual slides

A standard microscope was reconfigured as a virtual slide generator by adding a Prior Scientific H101 robotic stage with H29 controller and 0.1 microm linear scales and a Hitachi HV-C20 3CCD camera. Media Cybernetics Image Pro Plus version 4 (IP4) software controlled stage movement in the X-, Y-, and Z-axis, whereas a Media Cybernetics Pro-Series Capture Kit captured images at 640 x 480 pixels. Stage calibration, scanning algorithms, storage requirements, and viewing modes were standardized. IP4 was used to montage the captured images into a large virtual slide image that was subsequently saved in TIF or JPEG format. Virtual slides were viewed at the workstation using the IP4 viewer as well as Adobe Photoshop and Kodak Imaging. MGI Zoom Server delivered the virtual slides to the Internet, and MicroBrightField's Neuroinformatica viewing software provided a browser-based virtual microscope interface together with labeling tools for annotating virtual slides. The images were served from a Windows 2000 platform with 2 GB RAM, 500 GB of disk storage, and a 1.0 GHz P4 processor. To conserve disk space on the image server, TIF files were converted to the FlashPix (FPX) file format using a compression ratio of 10:1. By using 4x, 10x, 20x, and 40x objectives, very large gigapixel images of tissue whole-mounts and tissue arrays with high quality and morphologic detail are now being generated for teaching, publication, research, and morphometric analysis. Technical details and a demonstration of our system can be found on the Web at http://virtualmicroscope.osu.edu.