Applications - Presentations
Automated Processing of Bead-based Cytokine Multiplex Assays using Multiple Washer Platforms
Authors: Paul Held, Jason Greene, Peter Banks and Andreas Rieger, BioTek Instruments, Inc., Winooski, Vermont
A critical element with the use of Luminex® microspheres is the adequate removal of unbound materials from the beads during the assay procedure. With increased throughput demands, the use of automated washers such as the ELx50™ Microplate Strip Washer and the ELx405™ Microplate Washer has been employed. In order for an adequate wash process to take place, while at the same time providing for sufficient bead recovery to allow measurement determinations to be timely and statistically valid, the configuration of the washer settings is critical. The automated washing of polystyrene MicroPlex® Microspheres with filter plates requires coordination between fluid levels and evacuation time to avoid impregnating the beads into the filter matrix. Automated washing of MagPlex® Microspheres, which can be immobilized with magnets, is much less problematic than vacuum aspiration provided that the proper washer settings are employed. The spatial relationship between the localization of the magnetic beads by the magnet and the aspiration tubes is paramount for bead recovery. Here we describe the washer parameters associated with low residual volumes, good bead recovery and optimal washing of microspheres. Human Cytokine Multiplex Assay kits from Bio-Rad and Invitrogen were used to optimize the ELx50 and ELx405 washers.