Profiled Blotting Paper for Cryo-EM Grid Consistency

Solution Overview

Problem

Current methods for removing excess liquid from sample grids in cryogenic electron microscopy face challenges such as inconsistent blotting due to the geometry of the grid and holder configuration, which prevents effective contact between the blotting paper and the sample, and can damage the sample or require time-consuming and concentration-altering drying techniques.

Innovation Solution

A profiled region on the blotting paper is created to protrude into the holder's annulus, allowing it to approach the sample grid surface and efficiently wick away excess liquid, even when the outer surface of the holder prevents full contact, using standard and inexpensive materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If flat blotting paper is used with pre-loaded grid in holder, then the blotting paper contacts the outer surface of the holder, but the blotting is inconsistent because the paper cannot penetrate beyond the holder surface to reach the grid

Engineering Contradiction:

Improveblotting consistencyVSAvoidblotting effectiveness

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The blotting paper is transformed from a flat two-dimensional sheet into a three-dimensional structure with a profiled region that protrudes toward the grid. This dimensional change allows the paper to overcome the barrier created by the holder's outer surface and reach the grid surface for effective blotting.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The blotting paper is divided into different regions: a flat portion that contacts the holder's outer surface for positioning and support, and a profiled region that protrudes through the holder's annulus to contact the grid for blotting. This segmentation allows each region to perform its specific function effectively.

Inventive Principle:

Principle #1Segmentation

2Ease of manufacture

If grid is pre-loaded to holder before vitrification, then clipping difficulty is avoided, but the geometry creates a gap that prevents effective blotting contact

Engineering Contradiction:

Improvegrid loading easeVSAvoidblotting consistency

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The blotting paper is transformed from a flat two-dimensional sheet into a three-dimensional structure with a profiled region that protrudes toward the grid. This dimensional change allows the paper to overcome the barrier created by the holder's outer surface and reach the grid surface for effective blotting.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If flat blotting paper is used, then simple materials are employed, but the paper cannot reach the grid surface due to holder geometry

Engineering Contradiction:

Improvematerial simplicityVSAvoidblotting effectiveness

Core Design Contradiction:

Ease of manufactureVSEase of operation

Solution Approach 1:

The blotting paper is transformed from a flat two-dimensional sheet into a three-dimensional structure with a profiled region that protrudes toward the grid. This dimensional change allows the paper to overcome the barrier created by the holder's outer surface and reach the grid surface for effective blotting.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The blotting paper is divided into different regions: a flat portion that contacts the holder's outer surface for positioning and support, and a profiled region that protrudes through the holder's annulus to contact the grid for blotting. This segmentation allows each region to perform its specific function effectively.

Inventive Principle:

Principle #1Segmentation

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 solution enables consistent and reliable removal of excess liquid from sample grids, reducing the risk of grid damage and preserving sample integrity, while avoiding the need for specialized equipment or materials.

Implementation Method 1

the profiled region having a portion configured to protrude at least partially into a space created within a boundary formed by the rim of a holder for a sample grid... allowing it to approach the sample grid surface and efficiently wick away excess liquid

Methodology Applied

Scientific EffectCapillary action: Capillary Action

Implementation Method 2

such freezing must generally be performed very rapidly, with the aim of achieving sample vitrification (solidification into an amorphous, glass-like phase) without significant ice crystallization

Methodology Applied

Scientific EffectVitrification: Vitrification

Implementation Method 3

in whose perforations a small quantity of sample can be held (by surface tension effects)

Methodology Applied

Scientific EffectSurface tension: Surface Tension

Data Source

PatentUS20220410615A1Blotting material with profiled region, method of manufacturing same, and uses thereof

Publication Date: 2022.12.29 FEI CO

AI summary

The present invention describes a blotting material comprising a profiled region that has a portion configured to protrude at least partially into a space created within a boundary formed by the rim of a holder for a sample grid. Also described are methods for making such profiles and components used to make said profiles. There are also provided methods for removing excess liquid from a sample grid by bringing the profiled blotting material into association with the sample grid past the sample grid holder. Systems comprises means to hold a sample grid holder, means to hold the blotting paper, and means to bring the two together are also described.