Nanoliter homogenous ultra-high throughput screening microarray for lead discoveries and IC50 profiling

Area of Science:

• Biochemistry
• Assay Development
• Microfluidics

Background:

• Microfluidic technologies promise efficient ultra-high throughput screening and selectivity profiling.
• Existing systems require flexibility and cost-effectiveness comparable to plate-based assays.

Purpose of the Study:

• To introduce and evaluate the DiscoveryDot microarray system for biochemical assays.
• To demonstrate its compatibility with conventional assays and its efficiency in profiling enzyme inhibitors.

Main Methods:

• Utilized a 1" x 3" microarray with over 6,000 reactions, printing chemical libraries in 1-nl volumes.
• Employed piezo-activation for precise delivery of biochemical targets and detector chemistries (30-300 pl).
• Analyzed fluorescent signals using standard microarray scanners and software.

Main Results:

• Achieved >40-fold reduction in target/chemistry consumption and >10,000-fold reduction in compound consumption compared to 384-well plates.
• Demonstrated compatibility with conventional assays, achieving Z' factors >0.6 for various enzymes (caspases, MMPs, proteases, kinases, HDACs).
• Successfully performed 50% inhibitory concentration (IC50) profiling, generating over 300 IC50 measurements per chip.

Conclusions:

• The DiscoveryDot platform offers a highly customizable, cost-effective solution for high-throughput screening and selectivity profiling.
• Its compatibility and efficiency make it suitable for enzyme inhibitor IC50 studies.
• This system significantly reduces reagent usage while maintaining assay performance.