Application of mirrorball to aid antibody drug discovery
Two recent scientific papers [1,2] have demonstrated the benefits of mirrorball
(TTP Labtech) for the discovery of therapeutic antibodies. mirrorball®, an innovative high sensitivity microplate cytometer has been a significant, technical driving force enabling automated high throughput antibody assays to be performed.
The main approach to antibody screening is using either enzyme-linked immunosorbent assay (ELISA) or flow cytometry. Both of these methods are very sensitive, but can be laborious due to the requirement for multiple wash steps at different points through the protocol. This significantly limits the throughput that can be achieved. By using a plate-based approach, screening assays can be performed in 96-, 384-, and 1536-well plates, thus reducing reagent costs such as using the number of cells required per test. By virtue of mirrorball having 3 lasers and 6 detection channels which can simultaneously capture multiple fluorescence channels of data; cells and/ or beads can be color-coded to be used to identify binding with different cells or beads in the same well, for different targets.
Tickle, S. et al describes the successful design, construction and commissioning of a bespoke automated screening platform that incorporates mirrorball and how it can be used for screen antibodies against two specific targets . This automated platform can combine high throughput B cell culture screening with the identification and isolation of single, antigen-specific IgG-secreting B cells through a proprietary technique called ‘fluorescent foci’. More than 1 billion immune B cells can now be screened to provide a useful starting point from which to identify the rare therapeutic antibody.
In a second paper England, E. et al have evaluated a selection of typical cell- and bead- based assays that demonstrate how the multilaser capability of the mirrorball can be exploited to develop highly sensitive multiplex assays . This allows for identifying antibody cross-reactivity and selectivity but significantly without the loss of throughput. In this study the multiplexing of 2 antibody–cell binding assays (using different dyes) and 3 cytokine quantitation bead assays (using the same dye at different intensities) was developed. The results demonstrated an improvement of the sensitivity and efficiency of biologics screening.
Time is of the essence within drug discovery, in which more sensitive, multiplexed assays, as made possible by the mirrorball, may lead to more efficient, more streamlined screening processes and earlier identification of biologics therapeutics.
 Tickle, S. et al., J Biomol Screen (2014) Dec 29. pii: 1087057114564760
 England, E. et al., J Biomol Screen (2014) Nov 7. pii: 1087057114557776