Holographic microscopy, computational imaging see cells in 3D without contrast agents
Two École Polytechnique Fédérale de Lausanne (EPFL; Lausanne, Switzerland) scientists have developed a device that can create three-dimensional (3D) images of living cells and track their reaction to various stimuli without the use of contrast dyes or fluorophores. Yann Cotte and Fatih Toy have combined holographic microscopy and computational image processing to observe living biological tissues at the nanoscale.
Using their setup, 3D images of living cells can be obtained in just a few minutes at an incredibly precise resolution of less than 100 nm. And because they’re able to do this without using contrast dyes or fluorescent agents, the experimental results don’t run the risk of being distorted by the presence of foreign substances. The researchers developed, image by image, the film of a growing neuron and the birth of a synapse, caught over the course of an hour at a rate of one image per minute. As a low-intensity laser scans the sample from various angles, numerous images extracted by holography are captured by a digital camera, assembled by a computer, and “deconvoluted” in order to eliminate noise.
To develop their algorithm, the young scientists designed and built a “calibration” system using a thin layer of aluminum that they pierced with 70-nm-diameter “nanoholes” spaced 70 nm apart. The assembled 3D image of the cell, which looks as focused as a drawing in an encyclopedia, can be virtually sliced to expose internal elements such as the nucleus, genetic material, and organelles. In a company that’s in the process of being created and collaborating with startup Lyncée SA, they hope to develop a system that could deliver these kinds of observations in vivo, without the need for removing tissue, using portable devices. They will continue to design laboratory material based on these principles. Contact Yann Cotte at [email protected].
Gail Overton | Senior Editor (2004-2020)
Gail has more than 30 years of engineering, marketing, product management, and editorial experience in the photonics and optical communications industry. Before joining the staff at Laser Focus World in 2004, she held many product management and product marketing roles in the fiber-optics industry, most notably at Hughes (El Segundo, CA), GTE Labs (Waltham, MA), Corning (Corning, NY), Photon Kinetics (Beaverton, OR), and Newport Corporation (Irvine, CA). During her marketing career, Gail published articles in WDM Solutions and Sensors magazine and traveled internationally to conduct product and sales training. Gail received her BS degree in physics, with an emphasis in optics, from San Diego State University in San Diego, CA in May 1986.