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Published on: April 11, 2025
The ArrayGrid: a methodology for applying multiple samples to a single TEM specimen grid
Pablo Castro-Hartmann1, Gerard Heck, Jose M Eltit
1Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA 23298, USA.
Abstract:
High throughput transmission electron microscopy (TEM) is limited by the time that it takes to prepare each specimen and insert it on the microscope. It is further impeded by the deteriorating vacuum of the microscope upon frequent specimen cycling. Nevertheless, in most cases only a small fraction of the specimen is examined and sufficient to provide hundreds of images. Here we demonstrate that microarray technology can be used to accurately position picoliter quantities of different samples in a single TEM grid, with negligible cross-contamination. Key features are a contact-mode deposition on a robust formvar-carbon support. The TEM grid containing a microarray of different samples, the ArrayGrid, can also be negatively stained. The ArrayGrid increases the efficiency of TEM grid preparation and examination by at least by one order of magnitude, and is very suitable for screening and data collection especially in experiments that generate a multiplicity of samples.
Insights
Microarray technology enables precise picoliter sample placement on a single transmission electron microscopy (TEM) grid, significantly boosting efficiency. This ArrayGrid method accelerates specimen preparation and examination for high-throughput TEM applications.
Area of Science:
- Materials Science
- Microscopy Techniques
- Nanotechnology
Background:
- High-throughput transmission electron microscopy (TEM) faces limitations due to lengthy specimen preparation and vacuum disruption from frequent sample changes.
- Current TEM workflows are inefficient, with only small fractions of specimens typically examined, despite generating numerous images.
Purpose of the Study:
- To develop an efficient method for preparing and examining multiple samples in transmission electron microscopy (TEM).
- To overcome the time and vacuum stability limitations in high-throughput TEM.
- To introduce a novel TEM grid design for enhanced sample handling and analysis.
Main Methods:
- Utilized microarray technology for precise deposition of picoliter sample volumes onto a single TEM grid.
- Employed a contact-mode deposition technique on a robust formvar-carbon support.
- Developed the 'ArrayGrid' capable of holding multiple distinct samples and amenable to negative staining.
Main Results:
- Achieved accurate positioning of diverse samples on a single TEM grid with minimal cross-contamination.
- Demonstrated a significant increase in TEM grid preparation and examination efficiency, exceeding one order of magnitude.
- Validated the ArrayGrid's suitability for high-throughput screening and data collection from multiple samples.
Conclusions:
- The ArrayGrid, leveraging microarray technology, substantially enhances the efficiency of transmission electron microscopy (TEM) workflows.
- This method effectively addresses the challenges of specimen preparation time and vacuum stability in high-throughput TEM.
- The ArrayGrid is highly advantageous for experiments requiring the analysis of numerous samples, facilitating rapid screening and data acquisition.
