Microscope Addresses the Need for Speed

A technology used in projectors can create a high-resolution image 100 times faster than conventional microscopy equipment, which can be too slow to clearly document speedy biological processes.

The confocal microscope, developed at the University of Leicester, addresses the need for rapid-scanning microscopes with no loss in image quality. It bolts onto a regular microscope and projects patterns of light through a system of mirrors onto the microscopic sample. Only light that is precisely in the plane of focus returns along the same path and is reflected by the mirror onto a camera to form an image.

Schematic diagrams of the digital micromirror device (DMD) confocal optical pathway and the mirror arrangement for pinhole formation and scanning. The figure illustrates a 2 × 4 confocal configuration. (Images: PLOS ONE)

By programming the mirror device, the researchers can easily adjust the illumination pattern for different types of specimens and conditions. The microscope also takes out unwanted light that comes from regions of the specimen that are out of focus, helping to improve image quality.

The images produced can be scanned onto a computer at about 100 frames per second, showing biological processes such as cell activity at higher speeds than conventional devices, which typically scan around 1 frame per second.

“We built the device as there is a ‘need for speed,’ ” said Nick Hartell, who led the research. He is a professor in the university’s department of cell physiology and pharmacology. “I found out about this technology from its use in projectors and realized that it could be used to develop a microscope.”

The microscope has no moving parts, and its digital micromirror allows the size and spacing of mirrors to be altered to select the image quality and to adapt to various imaging conditions.

This technology will be helpful in various scientific fields, including biomedical research and neuroscience, the researchers said.

“Modern biological research, and modern neuroscience, depends upon the development of new technologies that allow the optical detection of biological events as they occur,” Hartell said. “Many biological events take place in the millisecond time scale, and so there is a great need for new methods of detecting events at high speed and at high resolution.”

Examples of wide-field and confocal images of biological specimens.

The device, funded by the Biotechnology and Biological Sciences Research Council, took three years to develop. Hartell is working with the university’s Enterprise and Business Development Office to commercialize the technology. He plans to use the device for his own work studying the cell mechanisms involved in memory storage in the brain.

“We are very excited because we have been able to go from a concept to a working prototype that is useful for my research into neuroscience,” Hartell said. “There is a good chance that we will be able to make a product and see that being used in labs in the UK and worldwide.”

The results were published online Aug. 24 in PLOS ONE.

In other microscopy news, researchers at six Italian research agencies have built a system that is 100 percent sharper than conventional light-sheet-based microscopy methods. (See: Merging Microscopy Methods Sharpens Brain Imaging)

For more information, visit: www.le.ac.uk