High-Throughput Screening (HTS)

Workflows Requiring High-Throughput Screening

The primary goal of HTS is to streamline drug discovery by rapidly analyzing a large number of potential biological modulators to identify those that have a desired effect on a specific target. HTS is commonly used in these workflows:

• Drug discovery: Identifying potential drug candidates that interact with specific biological targets.
• Functional genomics: Understanding gene function and identifying genes that play roles in specific pathways.
• Toxicology: Assessing the potential toxicity of various compounds.
• Pathway analysis: Identifying key players in specific cellular pathways.

An Overview of the High-Throughput Screening Process

Step 1: Sample and Library Compilation

This step entails selecting a biologically relevant target, typically a protein or cellular pathway known to play a role in disease or other processes of interest. Concurrently, a diverse collection of compounds is either created or procured. These compounds, which can number in the thousands to millions, form the “library” that will be screened for potential activity against the target.

Step 2: Development of a High-Throughput-Compatible Assay

Central to the HTS process is the design and application of an effective assay. This isn’t just any test; it’s meticulously tailored to gauge the impact of library compounds on a designated biological target. To be effective in an HTS context, the assay needs to be ultra-sensitive to even the minutest changes and flexible enough to manage vast sample volumes. Additionally, the transition to automation necessitates the assay’s optimization for devices like microplate readers, often meaning it’s tailored for formats such as 96-well or 384-well plates. Beyond this, ensuring the assay’s stability and reproducibility across a vast number of samples is paramount.

• Cell-based assays: Here, live cells take center stage. Compounds are tested within these cells to ascertain their effects, whether that’s a focus on cell health, proliferation, or distinct cellular reactions.
• Biochemical assays: Zooming in further, these assays engage with purified proteins or specific biomolecules to determine the influence of compounds. Often, this can be an exploration of enzyme kinetics or nuanced binding assays.
• Phenotypic assays: Taking a broader view, these assays dive into the realm of whole organisms. By introducing compounds to entities like zebrafish or C. elegans, researchers can monitor for any notable changes in phenotype

Step 3: Automation Infrastructure Setup

Given the sheer volume of samples and compounds, manual handling is impractical. Therefore, specialized robotic workstations are configured to automate the process. These workstations can handle tasks ranging from dispensing precise amounts of samples and compounds to transferring liquids between microplates. The entire setup is designed to minimize errors, maximize speed, and ensure consistent handling of every sample.

Step 4: Data Collection and Analysis

After the compounds have been screened using the assay, vast amounts of data are generated. Automated plate readers, imaging systems, or other detection methods are employed to collect this data. Specialized software then processes the information, analyzing it to identify compounds that showed desired effects, known as “hits.” This step is critical, as it sets the stage for further investigations and optimizations based on these promising compounds.