Solid Posts in Multiwell Plates for TIR Ligand Assays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current ligand binding assays face limitations in scaling to larger areas, such as 128 mm×86 mm, which are needed for clinical diagnostics and personalized medicine, and are prone to sedimentation issues due to open well plate designs.
Innovation Solution
The use of solid transparent posts in multiwell plates allows for total internal reflection ellipsometry without prisms or gratings, enabling simultaneous imaging of ligand-analyte interactions across larger areas and reducing sedimentation by immobilizing ligands on the side walls, allowing for multiplexed assays without the need for tags.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If traditional prism-based TIR imaging ellipsometry is used, then real-time imaging of binding events is achieved, but the field of view is limited to 1-2 cm² and cannot scale to larger multiwell plate areas
Solution Approach 1:
The invention divides the large-area detection surface into multiple small posts distributed across the multiwell plate. Each post acts as an independent TIR element, allowing the system to cover large areas (128 mm × 86 mm) without requiring a single large prism. The segmentation enables scaling to multiwell plate formats while maintaining manageable instrument complexity.
Solution Approach 2:
The invention uses simple cylindrical posts instead of complex prisms, making the detection surface disposable and interchangeable. This approach reduces instrument complexity by replacing expensive, complex optical components with simple, replaceable posts that can be configured for different assay formats.
2Measurement precision
If ligands are immobilized on the bottom of open wells, then binding events can be detected, but sediment from the sample falls onto the detection area during measurement
Solution Approach 1:
The invention transitions the ligand immobilization surface from a horizontal plane (bottom of well) to a vertical surface (side wall of post). This dimensional change allows the evanescent field to extend horizontally along the post side wall, keeping the detection area away from the sample bulk and preventing sediment from reaching the ligands during measurement.
Solution Approach 2:
The post structure acts as an intermediary between the sample and the detection system. By placing ligands on the post side wall rather than directly in the sample path, the post mediates the interaction while protecting the detection area from sediment contamination.
3Adaptability or versatility
If multiple ligands are arranged in arrays on posts, then the number of multiplexed assays increases, but the cost per assay should be reduced
Solution Approach 1:
The post structure serves multiple functions: it provides the TIR optical element, supports ligand immobilization arrays, and acts as a structural support within the well. This multi-functionality reduces the need for separate components, simplifying manufacturing and reducing costs while enabling high-density ligand arrays for multiplexed assays.
Solution Approach 2:
The posts are designed to be self-contained units that can be directly integrated into multiwell plates without requiring additional alignment fixtures or complex mounting structures. This self-service design simplifies manufacturing and reduces assembly costs while maintaining the capability for high-density ligand arrays.
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
This approach significantly increases the number of possible multiplexed assays, reduces costs per assay, and minimizes sedimentation issues, enabling cost-effective, high-throughput diagnostics with improved imaging capabilities.
Implementation Method 1
If the dimensions of posts are chosen so that a beam of light can be introduced through the posts in a manner to achieve total internal reflection from the side walls of the posts, ligands immobilized on the exterior face of each post will be in an evanescent field
Implementation Method 2
The resulting image data is compared to a stored image of the polarization phase distributions in the beam obtained prior to the exposure of the ligand array to a sample
Data Source
AI summary
Multiwell plates commonly used for immunoassay are increased in capacity and adapted for ease and speed of testing by forming a plurality of solid posts in each well of a plate. The posts and plate material and the dimensions of the posts are chosen to allow the immobilization of ligand patterns on an exterior wall of a post in a well and to permit a collimated beam of light directed to the post in a direction to achieve total internal reflection from a wall to generate an evanescent field in the plane of the ligands immobilized on the exterior wall of the post. The reflected light carries an image of localized intensity variations due to binding events between the ligand patterns and analytes in a sample introduced into a well. A cover plate seals the wells and provides for through holes for introducing sample material to the wells.