HCS Tools for Predictive Toxicology
To answer the need for better predictive toxicology, the Cellomics HCS Platform offers a platform of instrumentation, validated reagent kits, image analysis algorithms, and flexible data analysis tools. The platform is designed to address key toxicological endpoints in an efficient and robust manner.
For example, Thermo Scientific offers over 18 biologically validated HCS reagent kits for cell health and general cytotoxicity, several of which simultaneously investigate multiple indicators of cytotoxicity to get an accurate and complete picture of what is occurring to each cell in each well during treatment (Figure 1).
These kits examine key organelle health markers such as nuclear shape and size, cell membrane permeability, mitochondrial transmembrane potential, p53 and p21 activation, caspase activation, cytochrome C release, and oxidative stress. After using a Cellomics HCS reagent kit, the Cellomics BioApplication image-analysis algorithms provide hundreds of cytotoxicity-specific cell-level and well-level measurements to automatically assess samples for those indicators labeled by the kits.
For instance, cell health profiling is a bioapplication that is used in conjunction with a number of the reagent kits to evaluate 2-to 6-channel assays looking at multiple markers of cell health. Assay development and optimization with the BioApplication is straightforward, as the cell images and data produced by the algorithm can be examined with only two mouse clicks in the software’s convenient Protocol Interactive window (Figure 2).
Interacting with the images and seeing the resulting field’s data before a scan is completed allows for any necessary tuning of the algorithm before one commits to an entire plate scan, without the need to be an image analysis expert. For optimal decision-making power the BioApplication Event Wizard allows the user to combine multiple outputs to further subcategorize cells in a cytotoxicity assay (Figure 3).
User-defined criteria within the wizard classify populations at both the cell and well levels. By combining different algorithmic outputs in a cytotoxicity assay, the wizard can label cells in early/reversible toxicity if the cell has a decreased mitochondrial transmembrane potential but no cell membrane permeability, versus late/irreversible toxicity when the nuclei have fully condensed and the cell membrane has been impaired.
This rule-based approach allows rapid ranking of compounds based on multiple outputs, providing rich information to guide SAR and toxicology groups.
For those performing genotoxicity studies, Thermo Scientific offers 15 biologically validated reagents kits, again with an accompaniment of genotox-associated BioApplication image analyses. Whether investigating micronucleus formation, the MDM2 and p53 pathway, ATM, or Ku70/80, the kits cover a broad range of genotoxicity and DNA repair applications.
The Cellomics Micronucleus BioApplication was made specifically to identify genotoxicity in the form of micronuclei formation and was the first of its kind in the image-analysis industry. The algorithm has replaced many traditional in vitro toxicity assays as it is automated, more sensitive, scalable, and more objective than former methods.
The Thermo Scientific offering of Cellomics products for toxicology is primarily aimed at predictive toxicology, so that the compounds that make it through the preclinical testing phases have a greater chance of safely helping patients. This goal should benefit both the general public and pharmaceutical companies.
A recent industry report on early toxicology states, “With better predictions come increased efficiency, lower development costs, and drugs that reach the market faster. This would have a major effect on how drug discovery is perceived, both inside and outside the industry. This improvement would be a major milestone, adding credibility to the changes that have been taking place in drug discovery approaches.” Thermo Scientific considers HCS a tool for improving clinical outcomes and is continually working to develop and improve such tools.