Top96 Crystal Screen Design
Large-scale analysis of millions of crystallization trials revealed clear patterns in successful reagent combinations.
The Top96 screen distills the 384-condition JCSG Core Suite into the 96 most productive crystallization conditions.
The Top96 Cryoscreen adds optimal cryo-protectant pairings for each condition, solving harvesting and cooling challenges.
Benchmarking against PDB and internal data confirmed high success rates, with some conditions exceeding 70% effectiveness.
The streamlined screens benefit both high-throughput facilities and small labs by saving time, materials, and costs while boosting success rates.
- Top96 Conditions
- Top96 Poster
- Commercially availability: https://rigakureagents.com/products/block-jcsg-top96
The determination of protein structures through X-ray crystallography has transformed our understanding of biology and disease mechanisms. In recent decades, the surge in genome sequencing has dramatically expanded the number of protein structures available in the Protein Data Bank (PDB). High-throughput structural genomics efforts, such as those at the Joint Center for Structural Genomics (JCSG), demand strategies that maximize efficiency, control costs, and adapt processes for scalability.
JCSG developed a crystallization pipeline capable of screening vast numbers of proteins under diverse chemical conditions. Over 13 years, this approach generated an exceptionally large dataset: more than five million crystallization experiments, over 130,000 crystals, and 1,144 resulting PDB depositions. Analysis of this dataset revealed patterns in which conditions were most likely to yield diffraction-quality crystals—information essential for optimizing future screens.
From this data-driven refinement emerged the Top96 screen, a curated set of 96 crystallization conditions with the highest yield of successful structures. These conditions were distilled from the original JCSG Core Suite of 384 reagents by ranking each condition by its ability to produce harvestable crystals that resulted in PDB depositions. The team also created the Top96 Cryoscreen, which pairs each of the Top96 conditions with its most effective cryo-protection protocol. This addition serves a dual purpose: improving crystallization coverage and aiding in cases where crystal harvesting or cooling is a bottleneck.
The chemical diversity of Top96 spans organic precipitants, PEG variants, salts, and mixed systems, capturing both common successful formulations and novel conditions absent from commercial kits. Each condition’s success rate was validated against both internal databases and the PDB. Statistical analysis revealed that some conditions had success rates above 70%, while others showed more modest but still meaningful performance.
These refined screens are not only valuable for the scale of high-throughput projects but also for small research labs where protein availability is limited. They enable a more targeted approach, reducing redundancy, costs, and time, while increasing the odds of crystallization success. By applying lessons from over a decade of data curation, the JCSG Top96 and Top96 Cryoscreen offer a rational, evidence-based platform for structural biology that can accelerate and democratize the path from purified protein to solved structure.