The Z-factor (Z prime) is a dimensionless statistical metric. It measures the separation between the positive and negative control distributions on a screening plate. It accounts for both the difference in means and the variability of each control. A Z prime above 0.5 is considered acceptable for a reliable screen. Values above 0.6 indicate an excellent assay window. A low Z prime suggests excessive variability in the assay. It means you need to optimise cell density, reagent concentration, or detection method before committing a full compound library.
Bioactive Compounds and Compound Libraries
Compound Libraries for High-Throughput Screening
Pre-formatted compound libraries for faster screening setup and reproducible hits
They give your target identification or phenotypic screen a more consistent starting point than cherry-picking individual compounds. Libraries span diversity sets, focused bioactive collections, FDA-approved compound panels, natural product libraries, and fragment-based sets. Each type is tuned to a different discovery phase in your pipeline.
Compound libraries support your drug discovery, drug repositioning, and target identification work. Diversity libraries give you broad chemical space coverage for initial hit identification. Focused libraries centre on defined target classes, such as kinases, epigenetics enzymes, GPCRs, or ion channels. These give you pathway-centred screens with higher hit rates against known biology.
FDA-approved and clinically tested compound sets support your repositioning and toxicity reference work. Fragment libraries have a molecular weight below 300 Da and cLogP below 3. They serve your early-stage fragment-based drug discovery. Libraries are typically supplied in 96-well or 384-well plate format with DMSO stock solutions at defined concentrations. Each library comes with compound identity and purity data you can check.
Library content, plate maps, and pricing depend on current supplier catalogues, and stock levels change as those catalogues update.
Compound library type by discovery phase
1) Early hit finding, no prior target hypothesis. A diversity library fits here, for broad chemical space sampling. This suits phenotypic screens and target-agnostic assays where scaffold novelty matters to your project.
2) Target class known, hit rate matters more than novelty. A focused library fits here: kinase inhibitor set, epigenetics tool compound panel, or GPCR ligand collection. You get higher hit rates against related targets than from a diversity set of equal size.
3) Repositioning or safety reference work. An FDA-approved drug library fits here. Compounds carry clinical safety data and defined pharmacology. This shortens your path from hit to lead for repositioning studies.
4) Fragment-based drug discovery or structural biology. A fragment library fits here. Low-molecular-weight fragments bind weakly. Once binding sites are confirmed by SPR or crystallography, you can elaborate or link multiple fragments.
5) Natural product or extract-based phenotypic screen. A natural products library fits here. These sets cover chemical scaffolds not well represented in synthetic diversity libraries. They are useful when target novelty is a priority for your screen.
6) Confirming a hit or testing an analogue series. Single compounds from the Bioactive Compounds range suit this stage of your work better than a full library plate.
Applications
High-throughput screening
Diversity libraries in 96- or 384-well plates enable your automated screening against enzyme, receptor, or cell-based targets, with built-in Z-factor controls.
Target-class screening
Kinase, epigenetics, and GPCR ligand panels enrich hit rates against related targets, accelerating lead identification once your target class is known.
Drug repositioning
FDA-approved compound sets carry known pharmacokinetics, safety profiles, and mechanism of action, shortening your path from phenotypic hit to lead in repositioning work.
Fragment-based discovery
Fragment libraries hold low-molecular-weight compounds, 100 to 300 Da, for elaboration once binding sites are confirmed by crystallography, NMR, or SPR.
Natural product screening
Natural product libraries cover chemical scaffolds under-represented in synthetic sets, giving your phenotypic screens access to novel pharmacophores.
Hit confirmation
Once you confirm a screening hit, single compounds from the Bioactive Compounds range support analogue testing without a full library plate.
Product Catalog
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Compound Libraries
Pre-Formatted Compound Libraries for Faster Screening and Reproducible Hits
Frequently asked questions
A diversity library covers broad chemical space through scaffold diversity selection algorithms. This maximises the probability of finding at least one hit against any target when no prior structure-activity information is available. A focused library targets a specific protein family, such as kinases, GPCRs, or nuclear receptors, using pharmacophore or structural filters. This enriches for compounds likely to bind the target class. It achieves higher hit rates against that family but lower coverage of chemical space overall.
Most cell-based assays tolerate DMSO up to 0.1 to 0.5 percent (v/v) without significant effects on cell viability or phenotype. Sensitive primary cell types may show toxicity above 0.1 percent. Biochemical assays are generally more tolerant and accept up to 1 to 2 percent DMSO. You should still validate individual enzyme and binding assays by running a DMSO concentration-response curve. Compound libraries are typically supplied at 10 mM in DMSO. They are diluted to a final assay concentration of 1 to 10 micromolar, which keeps DMSO at or below 0.1 percent.
In fragment-based drug discovery, small molecules of 100 to 300 Da are screened at high concentrations, 0.1 to 1 mM. Biophysical methods such as surface plasmon resonance, NMR, or thermal shift assays detect this weak binding. Hits are then elaborated or merged into drug-like leads through structure-guided design. HTS screens drug-like compounds (350 to 500 Da) at low concentrations (1 to 10 micromolar) in activity assays. It identifies direct inhibitors without requiring structural information, but it explores a smaller fraction of accessible chemical space.
Product catalogs
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