Background

Many contemporary optical microscopy techniques fall short on resolving power (resolution), meaning structures finer than ~200 nanometers (nm) are very difficult to visualise. This is significantly limiting for life scientists in particular, because the cellular components and molecular interactions that underpin the fundamental processes of life occupy the scales of tens of nanometers. Super-resolution microscopy has emerged over the past two decades as a solution to this; however, most approaches rely on complex and very expensive optical instruments.

Expansion Microscopy (ExM) has emerged as a radically different super-resolution method that uses hydrogels instead of complex optics to physically inflate a sample, allowing structures as fine as 10-15 nm to be viewed with standard (e.g. confocal) microscopes. The simplicity of the ExM principles, coupled with its superior capabilities in visualizing three-dimensional cellular complexities, mean that there has been a steep uptake in ExM methods in many laboratories, with the number of peer-reviewed research articles using the technique doubling every 18 months in recent years.

Figure 1.

However, although very promising, low sample throughput, a reliance on manual dexterity when handling the hydrogels and lack of control of the hydrogel chemistry have typically hindered the widespread adoption of ExM as a standard technique.

Technology Overview

Researchers at The University of Sheffield have developed the first plate-based approach to ExM. The plates, which are designed to match the footprint of standard multi‑well, tissue culture plastic plates, allow a number of samples, for example; cultured cells, tissue explants or small organisms such as C.elegans, to be processed in parallel. Discreet, in‑plate gel casting apparatus provides for straightforward positioning and embedding of samples in a hydrogel, which can then be expanded to a larger size under highly controlled and reproducible conditions.

The design of these plates also allows for specific cells or features of the sample to be tracked and imaged, in situ, before, during, and/or after the gel expansion process with the use of a standard confocal or fluorescence microscope.

In parallel to this plate technology, the researchers have developed a low‑cost pipetting robot that is customised for the fast, efficient and accurate application of hydrogel precursors to each plate well. Successful use of the plate technology is not contingent on use of the robot, however, when utilised together, the technologies have the potential to revolutionise the ExM process.

Stage of Development

The team consider the development of both the plate and robot technology to be around Technology Readiness Level (TRL): 4/5.

Benefits

Proof of concept studies have shown that the use of the plate alone can significantly increase sample throughput rates, whilst reducing the amount of manual handling usually required for hydrogel preparation. Further gains are made through use of the pipetting robot, resulting in near elimination of the gel-to-gel chemistry variation that has, to date, been considered a key limitation in ExM.

The team believe that addressing these key issues is paving the way for the development of a low‑cost, robust and reproducible super resolution microscopy approach.

Applications

Although very promising, expansion microscopy is a developing field and so it is believed that initially, this technology will achieve maximum utility in an academic research setting. As use cases and examples emerge, it is anticipated that the technique will be adopted quickly by industrial R&D teams.

Opportunity

The team is looking for industrial partners to support the development and refinement of the technology towards marketable products. They are open to working with a single partner to develop both the robot and plate technology as a package, or multiple partners in order to develop the technologies independently.

They anticipate that the technology/ies will ultimately be manufactured and marketed by said partner/s under a commercial licence arrangement.

No patent applications have been filed to date as the team would prefer any such registrations to be informed by industrial utility and so steered by a commercialisation partner. No aspects of these technologies have been disclosed publicly.

High Throughput, High Resolution Microscopy

IP Status

Seeking