The BD FACSArray Bioanalyzer offers powerful, yet flexible, tools for the analysis of cellular and soluble proteins via a dual-array platform of multiplexed bead and flow cytometric capabilities. The FACSArray is capable of cell-based arrays including cell surface staining/immunophenotyping, intracellular phosphoprotein detection, intracellular cytokine analysis, cell cycle analysis and proliferation/apoptosis assays. In addition, the simultaneous quantification of multiple soluble proteins from cell culture supernatants, plasma or sera, can be performed by the FACSArray’s multiplexed bead array. High-content acquisition and analysis are possible for both platforms thanks to the incorporated microtiter 96-well plate sampler.
The FACSArray combines state-of-the-art flow cytometry components with a user-friendly interface in a compact benchtop unit smaller in size than most tabletop centrifuges. Technical specifications include: two-laser (532nm and 635nm), four-color fluorescence capability; a novel microtiter plate sampler; digital signal electronics for faster, more accurate processing (15,000 events per second); and intuitive software with experiment wizard-driven acquisition and analysis. The included software further simplifies the process of flow cytometry by providing ready-to-use or customizable templates, as well as support for batch analysis. . To accommodate all potential applications, BD offers over 1500 reagents for use with the FACSArray.
Our lab’s interest in the FACSArray lies in its cytometric bead array (CBA) application to quantify cytokines in undiluted human plasma, as its ability to makethequantification of circulating progenitor cells less complicated. I have previously run both the Human Angiogenesis and the Human Inflammation CBA kit assays, which involves the basic "sandwich assay" scheme using beads of varying fluorescent intensities to allow for the simultaneous measurement of five and six cytokines per sample, respectively. Using these two kits, I have determined the concentration of 11 cytokines from 43 samples, collecting the same amount of data as from 11 conventional ELISA experiments. From the same peripheral blood samples (using the appropriate antibody combinations), I have been able to quantify certain progenitor populations with relative ease and minimum color compensation, while obtaining positive results. BD offers more than a dozen pre-made, disease-specific CBA kits, as well as Flex Sets, which are kits that enable customized quantification for a combination of specific proteins. These aspects of the FACSArray collectively resulted in quite a powerful research tool, accelerating our lab’s progress.
The instrument has been designed to increase the sensitivity of protein quantitation, simplify the often dauntingly complex task of flow cytometry, and leave a small footprint in the lab (the instrument’s nickname is “The Post-doc Box”). As space requirements for the FACSArray are minimal, other aspects are inherently limited. For instance, while the inclusion of 532nm (green) and 635nm (red) lasers and a unique optical detection provide high sensitivity (even with the brightest fluorochromes in parallel), the FACSArray does not include the typical 488nm (blue) laser used to excite the often-used, but inferior, fluorochromes such as FITC and GFP. In addition, the instrument and reagents were designed with the use of smaller sample size in mind; therefore, the sampler accommodates only a 96-well plate format.
Daniel MacDonald
Senior Research Technician
The Children’s Blood Foundation, Department of Pediatrics
Weill Medical College of Cornell University, New York, NY