Rxivist logo

Genetically encoded phase contrast agents for digital holographic microscopy

By Arash Farhadi, Manuel Bedrossian, Justin Lee, Gabrielle H. Ho, Mikhail G. Shapiro, Jay Nadeau

Posted 12 Nov 2019
bioRxiv DOI: 10.1101/833830 (published DOI: 10.1021/acs.nanolett.0c03159)

Quantitative phase imaging and digital holographic microscopy have shown great promise for visualizing the motion, structure and physiology of microorganisms and mammalian cells in three dimensions. However, these imaging techniques currently lack molecular contrast agents analogous to the fluorescent dyes and proteins that have revolutionized fluorescence microscopy. Here we introduce the first genetically encodable phase contrast agents based on gas vesicles, a unique class of air-filled protein nanostructures derived from buoyant microbes. The relatively low index of refraction of the air-filled core of gas vesicles results in optical phase advancement relative to aqueous media, making them a positive phase contrast agent easily distinguished from organelles, dyes, or microminerals. We demonstrate this capability by identifying and tracking the motion of gas vesicles and gas vesicle-expressing bacteria using digital holographic microscopy, and by imaging the uptake of engineered gas vesicles by mammalian cells. These results give phase imaging a biomolecular contrast agent, greatly expanding the capabilities of this powerful technology for three-dimensional biological imaging.

Download data

  • Downloaded 525 times
  • Download rankings, all-time:
    • Site-wide: 90,126
    • In bioengineering: 1,784
  • Year to date:
    • Site-wide: 141,893
  • Since beginning of last month:
    • Site-wide: 119,561

Altmetric data

Downloads over time

Distribution of downloads per paper, site-wide