Scientists have adapted a method of astronomy to blur microscopic images

A team led by researchers at HHMI’s Janelia Research Campus has adapted a class of techniques used in astronomy to blur images of distant galaxies for use in the life sciences, giving biologists a faster and cheaper way to obtain clearer, sharper microscopic images. The findings are published in the journal Optics.

Astronomers have long figured out how to make the images of distant galaxies that their telescopes capture brighter and sharper. Using techniques that measure how light is distorted by the atmosphere, they can apply corrections to remove aberrations.

Microscopists are adapting these methods to produce clearer images of thick biological samples, which also bend light and create distortion. But these techniques — a class of methods called adaptive optics — are complex, expensive and slow, putting them out of reach for many labs.

Now, hoping to make adaptive optics more widely available to biologists, a team led by researchers at HHMI’s Janelia Research Campus has turned its attention to a class of techniques called phase diversity, which is widely used in astronomy but new to the life sciences.

These phase diversity methods add additional images with known aberrations to the blurred image with unknown aberration, thereby providing enough additional information to blur the original image. Unlike many other adaptive optics techniques, phase diversity does not require any major changes to the imaging system, making it a potentially attractive avenue for microscopy.

To implement the new method, the team first adapted an astronomical algorithm for use in microscopy and validated it with simulations. They also built a microscope with a deformable mirror, whose reflective surface can be changed, and two additional lenses – small modifications of the existing microscope that create the known aberration. They also improved the software used to perform phase diversity correction.

As a test of their new method, the team showed that it could calibrate a deformable microscope mirror 100 times faster than competing methods. They further showed that the new method can capture and correct randomly generated aberrations and provide clearer images of fluorescent beads and fixed cells.

The next step is to test the method on real samples, including living cells and tissues, and extend its use to more complex microscopes. The team also hopes to automate the method and make it easier to use. They hope the new method, which is faster and cheaper to implement than current techniques, could one day make adaptive optics available to more labs and help biologists see more clearly when peering deep into tissues.