December 10, 2010
Authors: Brad Larson and Peter Banks, BioTek Instruments, Inc.
Today’s pharmaceutical and biotech industry has seen an increased emphasis on generating the most relevant data possible in the most efficient manner. This has meant that many portions of the drug discovery process which typically implemented biochemical assays are now using cell-based assays with increased regularity. This is due to the fact that using intact cells provides a more in vivo-like environment when compared to biochemical assays, which use purified enzymes. This has created the need for instrumentation that is capable of handling cells and other assay components in a sterile manner. Large dispensing systems can be difficult to use with this type of assay due to their need for containment systems that can be expensive and difficult to implement. A smaller system, with multiple dispensing capabilities, which does not require its own containment, can deliver the accuracy, flexibility, and ease of use that is necessary for these assay processes.
Here we show the utility of a combination washer dispenser to be used in a cell-based assay format. The small footprint of the instrument allows it to be easily inserted into existing laboratory laminar flow hoods. The accuracy of the peristaltic pump, combined with the ability to autoclave the dispensing cassette, allow for sterile dispensing of cells, media, and other assay components. The instrument was used in combination with microplate pipetting and detection systems for automated sample processing. Testing was then performed with three cell-based assay processes representing varied areas of drug discovery research. The first was a triplex assay to measure Cytochrome P450 induction as well as cell viability. The second was a drug absorption assay to measure permeability and active transport of compounds across a cell layer using MDCKII-MDR1 and Caco-2 cells. The final procedure examined the ability to monitor the VEGF signaling pathway within a cell, leading to AKT phosphorylation. Validation data demonstrates the ability of the instrument to dispense cells, perform media exchanges, and deliver assay components to cell and assay plates. Further testing illustrates the ability of the complete system to be used for the increasing number of cell-based assays being implemented in today’s life science research laboratory.