A generic particle-based nonradioactive homogeneous multiplex method for high-throughput screening using microvolume...

Area of Science:

• Biochemistry
• Assay Development
• Drug Discovery

Background:

• High-throughput screening (HTS) is crucial for identifying novel drug candidates.
• Existing screening methods can be limited by radioactivity, complexity, or lack of multiplexing capability.

Purpose of the Study:

• To develop a novel, homogeneous, fluorescence-based binding assay for high-throughput screening.
• To validate the assay's performance for receptor-ligand binding.
• To demonstrate the assay's capability for multiplexing and miniaturization.

Main Methods:

• A fluorescence-based homogeneous binding assay utilizing Cy5- or Cy5.5-labeled ligands and immobilized receptors on particles (beads or cells).
• Detection of localized fluorescence using a modified microvolume fluorimeter (MVF).
• Image processing software for event enumeration and fluorescence intensity analysis.
• Development of a multiplex assay by immobilizing different-sized beads with distinct receptors (IL-1R and IL-5R).

Main Results:

• The MVF assay accurately determined IC(50) values for IL-1 receptor ligands, consistent with radioligand binding assays.
• A multiplex assay successfully quantified ligands for IL-1R and IL-5R simultaneously with comparable IC(50) values.
• The assay demonstrated reliable performance in a miniaturized 16-microl volume within an 864-well plate format.

Conclusions:

• The developed homogeneous, nonradioactive, miniaturizable, and multiplex-capable fluorescence assay is highly promising for screening compound libraries.
• This novel assay offers an efficient and versatile platform for drug discovery and development.
• The assay's ability to perform multiplexed and miniaturized screening enhances its utility for large-scale compound collections.