The FACSCalibur is a Fluorescence Activated Cell Sorter suitable for a variety of cell analysis applications. It is a very flexible, modular system that can be adjusted for specific needs. The base module is made up of a flow cytometer and the FACStation. The cytometer is equipped with a single argon ion laser (emission at 488nm) for performing cell analysis, while the FACStation provides a Macintosh-based software analysis platform. The basic instrument configuration allows a typical three fluorescence analysis, with green (FITC, fluorescein isotyocianate), yellow (PE, phycoerytrin) and red (PerCP, chlorophyll perydinine, or PE-Cy5, PE-cyanine5) fluorescent molecules.
You can expand the capabilities of the base module using different expansion kits: 1) a diodes red laser with light emission at 633nm (allows analysis of a fourth fluorescent signal); 2) the FACS Loader, an automatic sampler for up to 40 tubes; 3) the Multiwell Autosampler that loads multi-well plates; and, 4) a cell sorting system, which is aerosol-free and operates in a closed chamber allowing safety with infectious samples or sterility maintenance. In addition, separated cell fractions can be deposed directly into well plates.
Compared to the previous FACSCan model, this device has some improvements that make it much easier to use. First of all, a flux control system is available which allows adjustment of the sample intake speed. Second, the software provided with the FACStation can be used to auto-compensate the photomultipliers, a particularly useful characteristic if you have two lasers to set up. No big changes were made to the acquisition and analysis software. CellQuest for Macintosh is still used and no upgrades are currently available.
We have two FACSCaliburs in our lab; one equipped with the second laser option and the other fitted with the cell sorter. Both instruments are used mainly for diagnostic routine assays, like immunophenotyping, absolute cell counts, stem cells analysis and residual WBC (white blood cell) counts. I find the sorting module to be very useful, particularly for a small number of cell separations (larger demands require a more complete sorting system). It is fast, accurate and can be used efficiently with many kinds of cells thanks to the abundant numbers of fluorescent antibodies available today. The system equipped with the second laser has the advantage of speeding up routine analyses and reducing consumable demands, since more antibodies can be read simultaneously. Moreover, we have used this system for different projects with hepatic and stem cells and obtained reliable and repeatable results.
A design defect of the FACSCalibur is its liquid waste disposal system. Waste is made up of acquired samples mixed with transport medium and is collected in a very small tank that requires regular manual maintenance. Due to the nature of infectious materials commonly used, this can be a serious problem and poses a number of procedural issues. Even with this drawback, I can still say this system is an excellent choice for cell analysis, as well as being a good long-term investment for those requiring cytofluorimetric analyses.
Dr. Andrea Galli and Dr. Alessandra Cattaneo
University of Milan, Italy