Resources - Scientific Posters
Critical Washer Parameters for Washing BeadsDownload
October 12, 2012
Authors: Paul Held and Peter Banks BioTek Instruments, Inc., Winooski, Vermont; Harold N. Baker, Luminex Corp., Austin, Texas
A critical element of the use of Luminex® xMAP® microspheres (both MagPlex and MicroPlex) 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™ strip washer and the 405 Touch™ and EL406™ full plate washers has been employed. In order for an adequate wash process to take place, while at the same time providing for suffi cient bead recovery to allow measurement determinations to be timely and statistically valid, the confi guration of the washer settings is critical. Washing MicroPlex beads requires the use of vacuum aspiration, which can be problematic to automate due to variability of the fi lter plates and the starting sample matrix. Automated washing of MagPlex beads, which can be immobilized with magnets, is much less problematic 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. An antibody-based assay for thyroid stimulation hormone (TSH) was used to assess the ELx50 washer’s ability to wash Microplex polystyrene beads by vacuum fi ltration. An Avian Antibodies assay developed by Luminex was used to demonstrate the utility of the 405 Touch washer to automate the necessary wash steps of an antibody-based quantitative MagPlex bead assay via biomagnetic separation.
405 Touch Microplate Washer