Mix-and-read assays, first popularized as FMAT assays, were developed to overcome the problems associated with automating ELISAs particularly in cell-based methods. This new comparative study has used the FMAT assay to look at bead-based quantitation of a soluble protein (rabbit IgG) and antibody binding to EGF receptors expressed in A459 cells. The Mirrorball system scanned the entire well, and FMAT reported data from only a 1 mm2 area in each well. Beads were identified by laser scatter on Mirrorball and fluorescence on FMAT. The Mirrorball system could enumerate beads in all wells, in contrast to FMAT which could not detect all beads below 1 ng/mL rabbit IgG.

The study demonstrated that the performance of both systems was broadly similar. A full application note detailing this comparative study is available here