ArrayScan VTI: high-throughput screening goes confocal. Credit: CELLOMICS

High-throughput analysis of cellular processes is now entering the mainstream for drug discovery, but Pittsburgh-based Cellomics has been working in this area for some time. Founded in 1996 to focus on the automated analysis of cell arrays, Cellomics offers an integrated package of imaging platforms with full environmental control, bioassays and bioinformatics and analysis software.

The firm produces two core platforms: KineticScan analyses cellular and intracellular interactions over time, and can deal with either live or fixed cells, whereas ArrayScan generates information-rich data on the effects of drug candidates on cells and is aimed at target validation and lead optimization applications.

The modular architecture of ArrayScan VTI, the fifth and latest generation of the system, allows users to increase optical capabilities by adding filters and objectives, and software to handle and visualize data better. The system also addresses the two conflicting aims of array screening — the need for high throughput, and the need for information-rich, high-resolution data including three-dimensional imaging.

“It takes time to acquire various z-positions and use higher magnification, so throughput is at odds with 3D resolution,” says Martin Pietila, high-content screening instrumentation product manager at Cellomics. “For the first time we've been able to offer both operating modes.”

The latest ArrayScan includes the ApoTome optical-sectioning device developed by Carl Zeiss Microscopy of Jena, Germany, which can be deployed as required. ApoTome allows confocal-style three-dimensional imaging with a conventional fluorescence microscope, by projecting the image of a grid structure into the focal plane of the specimen. Combining images with the grid in three positions within this plane produces an optical section with improved contrast and resolution in the z-axis.

“This affords scientists precise control of sampling applications,” Pietila says. “It allows them to take multiple measurements of different z-positions to look for structures with variable distribution in three dimensions.” The ArrayScan VTI can analyse up to 150 96-well plates a day using ApoTome, or 260 a day without.

T.C.