Sub-Millimeter Drop-Carrier Particles for Uniform Assay Volumes
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Solution Overview
Problem
Current methods for compartmentalizing fluids in single-molecule or single-cell assays, such as digital PCR and digital ELISA, face challenges with non-uniform compartment sizes, high costs, and difficulty in introducing solid supports and unique barcodes, particularly in microfluidic systems.
Innovation Solution
The development of sub-millimeter scale drop-carrier particles with well-defined 3D structures and chemical functionalities that allow for the creation of monodisperse fluid compartments, which can be easily mixed and reacted using gravitational or magnetic forces, and are compatible with standard benchtop equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If microfluidic approaches are used to create monodisperse emulsions of drops or droplets, then uniform compartment sizes are achieved, but instrument cost and device complexity increase significantly
Solution Approach 1:
The patent replaces complex microfluidic mechanical systems with a simple gravity-based emulsification approach. Macroscopic droplets are generated by gravity-driven flow through a simple nozzle or capillary, eliminating the need for microfluidic pumps, pressure controllers, and precision fabrication. This substitution of mechanical complexity with gravitational forces achieves uniform droplet sizes without requiring expensive microfluidic instrumentation.
Solution Approach 2:
The patent employs disposable polymeric microcapsules that can be easily manufactured and discarded, replacing expensive, complex microfluidic chips and instruments. These microcapsules serve as the compartmentalization medium and can be produced through simple extrusion or 3D printing processes, significantly reducing the cost barrier for digital assay implementations.
2Productivity
If microfluidic pumping systems are used to generate droplets, then controlled droplet formation is achieved, but dead-volumes increase and sample volume efficiency decreases
Solution Approach 1:
The patent extracts and eliminates the dead-volumes associated with microfluidic pumping systems by using a gravity-based droplet generation approach. The simple nozzle or capillary structure has minimal internal volume, and the gravity-driven flow ensures that reagents and samples are efficiently transferred without being trapped in dead-zones. This extraction of the problematic microfluidic system entirely removes the source of dead-volumes.
3Adaptability or versatility
If solid surfaces are introduced into microwell arrays or droplets for reagent introduction, then unique barcodes and affinity reagents can be provided, but Poisson statistics limit the reliability
Solution Approach 1:
The patent incorporates solid surfaces, unique barcodes, and affinity reagents directly into the microcapsule structure during the manufacturing process. This preliminary incorporation ensures that every microcapsule receives the necessary components without relying on random distribution processes. The solid surfaces can be applied via coating or embedding techniques before droplet formation, guaranteeing consistent reagent presence and eliminating Poisson statistical limitations.
Solution Approach 2:
The patent creates composite microcapsule structures combining polymeric matrices with embedded solid surfaces, barcodes, and affinity reagents. These composite structures integrate multiple functions into a single unit, ensuring reliable reagent introduction and barcode assignment. The composite approach allows for controlled incorporation of solid components that would otherwise be difficult to integrate into liquid-based droplet systems.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables uniform reaction volumes and efficient introduction of reagents and barcodes without complex instruments, facilitating cost-effective single-molecule and single-cell assays using standard imaging and flow cytometry.
Implementation Method 1
The 3D structures or particles that are described herein are referred to as drop-carrier particles. The drop-carrier particles allow the selective association of one solution (i.e., a dispersed phased) with an interior portion of each of the drop-carrier particles, while a second non-miscible solution (i.e., a continuous phase) associates with an exterior portion of each of the drop-carrier particles due to the specific chemical and/or physical properties of the interior and exterior regions of the drop-carrier particles.
Implementation Method 2
which can be easily mixed and reacted using gravitational or magnetic forces
Implementation Method 3
which can be easily mixed and reacted using gravitational or magnetic forces
Data Source
AI summary
Sub-millimeter scale three-dimensional (3D) structures are disclosed with customizable chemical properties and/or functionality. The 3D structures are referred to as drop-carrier particles. The drop-carrier particles allow the selective association of one solution (i.e., a dispersed phased) with an interior portion of each of the drop-carrier particles, while a second non-miscible solution (i.e., a continuous phase) associates with an exterior portion of each of the drop-carrier particles due to the specific chemical and/or physical properties of the interior and exterior regions of the drop-carrier particles. The combined drop-carrier particle with the dispersed phase contained therein is referred to as a particle-drop. The selective association results in compartmentalization of the dispersed phase solution into sub-microliter-sized volumes contained in the drop-carrier particles. The compartmentalized volumes can be used for single-molecule assays as well as single-cell, and other single-entity assays.