Discussion

Whilst high content imaging is a powerful and flexible screening technology, lengthy read times and associated high data volumes present challenges. A method was developed to reduce the time required for automated high content (HC) imaging (ImageXpressMICRO).

This method involved hit well identification using a whole well fluorescence pre-read on a non-imaging plate reader (Envision). Filtering the output from this pre-read (signal above background) enabled targeted imaging of only wells of interest.

This was applied to a metabolism target as an assessment of an alternative approach for identification of false positives. Primary HTS screening output of 5500 384-well plates were processed using the non-imaging pre-read. Filtering to only wells of interest meant a >40 fold reduction in the high content reader time per plate, image analysis time and associated data storage costs. This further enabled capture of up to 4 images from those wells of interest, consistent with HTS-scale plate processing.

Exploiting this approach, the entire compound collection was screened in the same time that previously only 2% of the collection would have been assessed. This method delivered a more biologically relevant high content readout to the project team and has demonstrated this route as an option to progress future cellular screening targets.