High-Throughput Screening (HTS) Services

Researchers may screen their own library or a full subset of a Charles River library. Alternatively, our CADD experts can work with you to design a targeted screening selection. Approaches for creating a curated selection include:

• Structure-based virtual screening from crystal structures or homology models
• Ligand-based virtual screening based on known active compounds
• Similarity / substructure searching around known active compounds
• Statistical / categorical model generation based around known active compounds
• Physicochemical property-driven selections

Researchers can also take advantage of computational selection for plate-based screening to create sets with desirable characteristics, such as maximizing structural representation, or bias towards known activities or property profiles.

At Charles River, our drug discovery scientists bring deep expertise and extensive experience in HTS assay development, tailored to both target-based and phenotypic screening approaches. For target-based, we excel in developing and optimizing both biochemical and cellular HTS assays, utilizing cutting-edge technologies to ensure precise target engagement.

Our team is adept at engineering novel cell lines for custom target engagement assays and reporter-based systems, enhancing specificity and sensitivity. In phenotypic HTS, we leverage a wide array of leading assay platforms to identify compounds that impact complex biological pathways. Additionally, we integrate orthogonal assays into our screening cascades, ensuring comprehensive validation of hits by assessing activity across multiple mechanistic readouts, offering a thorough and streamlined approach to hit identification and lead optimization.

We ensure the highest level of assay validation using a variety of advanced software platforms, including robust quality management systems (QMS). Our data is processed through leading tools such as IBDS Activity Base, Titian Mosaic, Dotmatics, and GeneData Screener, ensuring precision and reliability throughout the screening process. We are committed to maintaining the accuracy, integrity, and confidentiality of all data generated via our high-throughput screening (HTS) platform, providing our clients with secure and transparent access to their results every step of the way.

Our compound management is executed with best-in-class equipment, including Titian management software and Echo liquid handling instruments. Our processes are designed to add simplicity and peace of mind, allowing you to focus on your discoveries.

Through advanced automation, we can facilitate complex logistics, rapid plate preparation, and integrated projects, seamlessly bringing together screening with chemistry, biology, ADME, and more. Our fully automated HTS platform allows you to screen in-house or client libraries of up to and exceeding one million compounds as a single or pooled compound(s) per well. We also have the capacity to store a copy of your library for multiple screening campaigns.

Our Medicinal Chemistry experts play a key role in your high-throughput screening program to ensure the successful identification and progression of high-quality chemical matter. With extensive experience in distinguishing true hits from false positives, we apply rigorous validation techniques, such as counter-screening and orthogonal assays, to establish confidence in the chemical matter identified during HTS campaigns.

Our medicinal chemists work closely with biologists to develop structure-activity relationships (SAR) around promising hits, providing a clear path to optimize potency and selectivity. In addition, we meticulously corroborate the mode-of-action (MoA) and confirm target engagement through biophysical and biochemical assays, ensuring that the compounds engage the intended target in a biologically meaningful way. By focusing on chemical diversity and identifying the most suitable, high-quality chemical series, we enable smooth progression from hit identification towards hit-to-lead, laying the foundation for a robust drug discovery pipeline.

Maximize your high-throughput screening investment by following up your initial hit matter with our proprietary CADD-driven hit expansion protocol. Prioritized hits from your HTS can be used to computationally select related, unscreened, compounds from our extensive collection or from external vendor libraries. Follow-on screening of these compounds allows you to enlarge your pool of hit matter into wider chemical space and generate additional understanding of the structure-activity relationship (SAR) of compound series.

High-throughput Screening (HTS) is a hit identification approach in which many compounds (generally >10 k) are tested in a single screening activity. An HTS workflow will typically consist of:

• Assay development or assay transfer
• Compound set selection
• Pilot screen
• Primary screen
• Hit confirmation
• Potency determination
• Hit expansion

We use the below definitions to describe high-throughput screening:

• HTS (diversity screening): A screening paradigm that enables coverage of broad chemical diversity in a single activity, with few target prerequisites. Hundreds of thousands of compounds can be screened in each experimental run, in order to deliver fast, efficient, and (most crucially) consistent data.
• Phenotypic HTS: A diversity screening approach which employs a functional cellular assay as the primary screen (ideally in a disease-relevant cellular model). In this instance, it will be unclear as to mode of action (MoA) of the compounds that appear as "hits."

Charles River has extensive experience in HTS assay development and HTS cascade design. Our expert teams can help design your entire cascade, developing all assays from scratch if required. We can source or generate high-quality screening protein and build transient or stable cell lines as required.

We take many factors into account to validate the assays for your HTS cascade, including assay robustness, reproducibility, reagent stability, and overall cost. Where known modulating compounds / perturbant exist, these will be used to validate the assay system. We establish and monitor standard assay QC criteria including Z', Signal:background, CV, Inter+Intra plate effects (along with ensuring all equipment used is QC'ed appropriately).

Validation is key for success as HTS assays need to be robust enough to find hits from a single point. QC criteria for your screen will be agreed and set during assay development and then applied across your HTS campaign.

Charles River has experience across a broad range of assay technologies. We can help advise on the best course of action once we know details of your target(s) or your phenotype of interest. The decision around screening approach / technology could be based on several factors, such as budget/reagent availability, or desired MoA, for example. Our expert team is available for consultancy on all technology types used across hit identification, from simple biochemical systems to complex multi-parametric cellular endpoints (such as high-content imaging [HCI], or automated E-Phys).

Charles River has a number of exclusive libraries, including our Lead-Like and Diversity sets, and several libraries designed for specific biological target classes. We also have various annotated sets to help drive phenotypic programs and can provide virtual screening services for hit identification, which can run in parallel to or in place of wet lab HTS, dependent on your project needs.

Charles River offers flexibility in the choice of compounds for screening, including selection of entire libraries, targeted selection, and computational selection of screening plates across a selection of different libraries. We can provide SD files to you, or our in-house CADD team can help select the relevant compound set for your needs (either maximizing diversity or biasing against additional criteria).

Your project timeline depends on multiple factors, and you will receive a clear estimate once we know the details of your project. Typically, a fast biochemical screening campaign of reasonable scale in 1536 would likely be approximately 20 weeks, if following a traditional cascade (primary screen – hit confirmation – potency determination). However, an HTS campaign could range anywhere between 4-40 weeks depending on the assay type, technology, cascade complexity and size of the library screened. Fast-Track HTS campaigns are typically rapid, reducing the overall campaign completion time significantly.

Our tailored and Fast-Track HTS programs are each designed to meet different needs and requirements. While Fast-Track HTS is available at a lower fixed cost and accelerated campaign delivery, all aspects of the program meet the same high standard as all Charles River services, with speed and price-point achieved through standardization and a streamlined screening cascade. Talk to our expert team to discuss which approach best suits your research objectives and anticipated program progression.