During the last few years pharmaceutical and biotech companies have adopted high content screening (HCS) extensively in their drug discovery research. High content analysis uses automated microscopy, to capture cellular images, and analyze them using software to quantitate complex cellular events. This includes cellular morphology, biochemistry, and differentiation, translocation of proteins, proliferation, and apoptosis. The specialized software recognizes patterns from the images and quantify the differences between wells as accurately as possible without bias. Novel reagents, instruments and technology have significantly improved the quality and speed of the screen and have opened up the technology to a wider user base. In the two part series we will discuss some of the most commonly used application for high content screen. We will also discuss some of the reagents, and hardware currently available on the market n this fast growing field. There has been a steady increase in the adoption of HCS in pharmaceutical and biotech companies specially employing engineered cell lines or primary cells.
Most commonly used application for the HCS is in oncology, neurobiology, in vitro toxicology, immunology, cardiovascular biology, and endocrinology. HCS is widely used for target identification/validation, secondary screen, lead optimization and compound profiling. Some of the most relevant application for the HCS include, signaling pathway analysis, morphological changes, multiplexed assays, translocation, cell proliferation, cell migration, cell differentiation, kinases, toxicological studies, and reporter assays. Some of the assays such as cell migration assays include trans-well migration, lateral migration or invasion of tumor cells through a matrix coated membrane towards a chemotactic stimuli. High content analysis for neuroscience application include, quantifying neurite outgrowth, transcription factor translocation, neuron and synapse number, cell proliferation, receptor internalization, migration and apoptosis.
Data management and informatics are critical aspects of the high content screen. Typically multiple images of the micro plate wells are captured at different magnifications and sometimes stitched together and analyzed using specialized software programs. Usually raw images are stored in high capacity storage devices. Users need to implement both hardware and software systems in place to handle the large volumes of data generated after each screen in order to successfully execute a high content screen. From the images captured, software programs are able to recognize patterns and extract relevant quantifiable data in order to compare between compounds screened. This will allow comparisons of multiple parameters of complex cellular characteristics in response to various potential drug candidates.
In summary we have discussed the increasing adoption of high content screen in drug discovery by small to medium biotech companies, and established pharmaceutical companies. Potential applications in various areas of drug discovery are also discussed. The critical nature of specialized hardware and soft ware necessary to store and analyze large volumes of data is also emphasized. In the next article we will cover some of the major vendors offering reagents, hardware, and software systems to implement the high content screen.