Microfluidic Droplet Isolation for Protein Crystallization
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Solution Overview
Problem
Existing methods for determining optimal concentrations for protein crystallization are cost-prohibitive due to the need for macro-portions of multiple aqueous solutions, especially when working with expensive proteins.
Innovation Solution
A microfluidic system comprising a droplet isolation device and an injection system, which allows for the simultaneous generation and storage of isolated droplets of aqueous solutions by introducing two different aqueous solutions into a chamber without mixing, based on pressure levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If macro-portions of multiple aqueous solutions are mixed in testing trays, then protein crystallization can be tested, but the cost becomes prohibitive due to the large volume of expensive proteins required
Solution Approach 1:
The patent divides the macro-scale testing tray into multiple micro-scale droplets, each containing a specific concentration of protein and precipitant. This segmentation allows testing of multiple conditions simultaneously using minimal amounts of expensive protein, as each droplet is isolated and requires only nanoliter volumes of reagents.
Solution Approach 2:
The patent introduces an aqueous bridge as an intermediary substance that connects two immiscible aqueous solutions (one containing protein, the other containing precipitant) without allowing them to mix. The bridge allows controlled diffusion of molecules across the interface, enabling concentration gradients to form naturally while preventing bulk mixing that would waste the expensive protein.
2Adaptability or versatility
If multiple aqueous solutions are introduced into a chamber, then concentration testing is enabled, but the solutions may mix prematurely before reaching the testing chamber
Solution Approach 1:
The aqueous bridge acts as a mediator between two immiscible aqueous solutions, allowing controlled molecular exchange while maintaining physical separation. This enables the system to deliver multiple concentrated solutions to the testing chamber without premature mixing, preserving the stability of each solution's composition until the desired location.
Solution Approach 2:
The patent replaces mechanical mixing or pumping systems with a passive diffusion-based approach. By using immiscible aqueous solutions and an aqueous bridge, the system allows concentration gradients to form through controlled diffusion rather than active mixing, eliminating the need for complex mechanical control while maintaining solution separation.
3Reliability
If traditional crystallization trays are used, then protein crystallization can be observed, but the macro-sized volume makes it cost-prohibitive for expensive proteins
Solution Approach 1:
The patent segments the traditional macro-scale crystallization tray into multiple micro-scale droplets, each capable of supporting protein crystallization. This segmentation reduces the total volume of expensive protein required from milliliters to nanoliters, making testing of multiple concentrations economically feasible while maintaining the reliability of crystallization observation.
Solution Approach 2:
The patent transitions from two-dimensional planar crystallization trays to three-dimensional droplet-based systems suspended in immiscible phases. This dimensional change allows for better control of concentration gradients and improved mass transport to the droplet interfaces, enhancing crystallization reliability while minimizing reagent volumes.
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 the efficient testing of multiple solution concentrations for protein crystallization while minimizing waste, thereby reducing costs associated with expensive proteins.
Implementation Method 1
The at least one capillary valve is configured to allow for the at least two different aqueous solutions to be introduced into the at least one chamber without mixing prior to entering the at least one chamber based at least in part on pressure levels of the at least two different aqueous solutions
Implementation Method 2
simultaneous generation and storage of isolated droplets of aqueous solutions
Data Source
AI summary
Systems and methods are provided for producing isolated microfluidic droplets. In one aspect, a microfluidic system comprises a droplet isolation device and an injection system. The droplet isolation device includes at least one isolation unit and at least one capillary valve. The isolation unit has at least one chamber configured to receive at least two different aqueous solutions without mixing prior to entering the at least one chamber based at least in part on pressure levels of the at least two different aqueous solutions. The injection system includes an aqueous inlet, a non-aqueous inlet, a bypass outlet, a working fluid outlet, and a loading chamber. The injection system is configured to allow for a predetermined amount of each of the at least two different aqueous solutions to be delivered to the droplet isolation device sequentially.