WHAT ARE SOME OF THE CHALLENGES ASSOCIATED WITH PHENOTYPIC ASSAYS?
Scaling-up to run large screens of hundreds of multi-well plates per week can often be a challenge when using imaging. Often, screening campaigns are run as large batches of multi-well plates over an extended periods of week or months at a time and with large time gaps between each run. However, it is imperative that data and assay performance are consistent between runs so that data can be compared and compounds ranked. The first challenge with using imaging in screening campaigns is scaling up. Because imaging has traditionally been a very low throughput and manual process, prototype imaging-based assays are often developed using individual coverslips or in some cases 24 or 96 well plates. Scaling up from 24-well or even 96-well plates to 384-well plates can be tedious and time-consuming. Most worrying though is that sometimes assays developed in these lower throughput formats simply do not scale-up and months of work is lost. We avoid this scaling-up problem by developing ALL of our assays from Day 1 in 384-well format and using the same reagents, liquid handling and imaging instrumentation to develop any prototype as we do when screening in full production mode. This strategy reduces overall project costs dramatically by eliminating the scaling-up phase entirely. Most importantly, since in 384-well format we can test and optimize a myriad of assay conditions in parallel, this strategy also increases the likelihood that your prototype assay will be developed successfully and on-schedule!
Phenotypic assays that use imaging, specifically automated quantitative fluorescence microscopy or high content screening (HCS), bring their own set of challenges. We’ve tried to address how we tackle these challenges but if you have other concerns please contact us.