Close

Search

Search Menu
Photonics Media Photonics Marketplace Photonics Spectra BioPhotonics EuroPhotonics Vision Spectra Photonics Showcase Photonics ProdSpec Photonics Handbook

CHIDO Offers Insight into Cells, Molecules

Facebook Twitter LinkedIn Email Comments
ROCHESTER, N.Y., Oct. 26, 2020 — Researchers at the University of Rochester and the Fresnel Institute in France developed a method for visualizing molecules’ position and orientation in 3D, as well as their oscillations. The technique could allow for greater insights into the biological processes involved when a cell and the proteins that regulate its functions react to a COVID-19 virus.

The technology, coordinate and height superresolution imaging with dithering and orientation (CHIDO), designed and built by co-lead authors Valentina Curcio, a Ph.D. student in Sophie Brasselet’s group at the Fresnel Institute, and Luis A. Aleman-Castaneda, a Ph.D. student in Miguel Alonso’s group at the University of Rochester, is based on a device crafted by Thomas Brown about 20 years ago.
The spatially-varying birefringence phase plate has a birefringence distribution with trigonal symmetry. In effect, it can produce beams that have every possible polarization state. Courtesy of J. Adam Fenster/University of Rochester.
The spatially varying birefringence phase plate has a birefringence distribution with trigonal symmetry. In effect, it can produce beams that have every possible polarization state. Courtesy of J. Adam Fenster/University of Rochester.

CHIDO features a glass plate subjected to uniform physical stress all around its periphery. The device is placed in the Fourier plane at the back of a fluorescence microscope, where it is able to transform the image of a single molecule into a distorted focal spot. The shape of the molecule directly encodes the 3D information.

The microscope, with CHIDO incorporated, is then able to precisely monitor the position, orientation, and oscillations of single cells.

When a protein changes shape, it exposes other atoms that enhance the biological process, so the change of shape of a protein has a significant effect on the other processes inside the cell, said Brasselet, director of the Fresnel Institute. A way to monitor this change of shape is to use CHIDO to observe the orientation of fluorescent molecules attached to the protein under investigation.

The spatially varying birefringence phase plate has a birefringence distribution with trigonal symmetry; it can produce beams that have every possible polarization state.

“This is one of the beauties of optics,” Brown said. “If you have a device that can create just about any polarization state, then you also have a device that can analyze just about any polarization state.”

The origin of the device stems from an investigation of unusual polarization patterns in optical beams, some of which exhibited a spoke-like radial pattern. Ph.D. student Kathleen Youngworth demonstrated on a tabletop that, when tightly focused, the beams exhibited polarization components that pointed in almost any direction in three dimensions.

Another Ph.D. candidate, Alexis (Spillman) Vogt, attempted to replicate the effect by applying physical stress to the edges of a glass cylinder.

“Metal expands at a faster rate when you heat it than glass does,” Brown said, “and so you could heat the glass and metal up very hot, insert the glass in the middle of the metal, and as it cools down, the metal would shrink and create a tremendous force on the periphery of the glass.”

The group then fabricated a selection of its samples, fitting them in metal rings so that they could be used with a confocal microscope, which involved heating the components.

In the process, the group inadvertently applied more stress than called for with one of the plates, and, as soon as a team member handled it, the plate exhibited unusual and distinct qualities. The Rochester researchers introduced the term “stress engineered optic” to describe the elements. Later, they realized that the windows could be used to explore additional and even untested concepts in microscopy.

The research was published in Nature Communications (www.doi.org/10.1038/s41467-020-19064-6).


Photonics.com
Oct 2020
GLOSSARY
fluorescence microscopy
Observation of samples using excitation produced fluorescence. A sample is placed within the excitation laser and the plane of observation is scanned. Emitted photons from the sample are filtered by a long pass dichroic optic and are detected and recorded for digital image reproduction.
polarization
With respect to light radiation, the restriction of the vibrations of the magnetic or electric field vector to a single plane. In a beam of electromagnetic radiation, the polarization direction is the direction of the electric field vector (with no distinction between positive and negative as the field oscillates back and forth). The polarization vector is always in the plane at right angles to the beam direction. Near some given stationary point in space the polarization direction in the beam...
birefringence
The separation of a light beam, as it penetrates a doubly refracting object, into two diverging beams, commonly known as ordinary and extraordinary beams.
Research & TechnologyopticsRochesterUniversity of RochesterUniversity of Rochester’s Institute of OpticsMicroscopyfluorescence microscopyabbe diffraction limitAbbe limit3D imagingpolarizationpolarization analysisoscillateconfocalconfocal microscopebirefringencebirefringentsingle moleculeAmericasEuropecollaboration

Comments
back to top
Facebook Twitter Instagram LinkedIn YouTube RSS
©2020 Photonics Media, 100 West St., Pittsfield, MA, 01201 USA, [email protected]

Photonics Media, Laurin Publishing
x We deliver – right to your inbox. Subscribe FREE to our newsletters.
We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.