Fish on Fire

Scientists have been lighting the dark inside living tissues with fluorescent molecules for decades. Continuing to tinker with new approaches, the chemicals inside this zebrafish go a step further – the difference, perhaps, between street lamps and security lights detecting something moving in the dark (albeit 10000 times smaller). Zebrafish have much to tell us about our similar but more complex developing tissues. Spreading out inside the fish, each spot of light is a protein 'switch' that senses nearby calcium ions by changing shape – picking out sparks of calcium common in the early nervous system with tiny blazes of far red light using fluorescence lifetime imaging microscopy. The colour choice is deliberate – far red light can shine from deep in the fish’s tissue and allows more common, green, blue and red fluorescent proteins to be used in combination and hinting at more ingenious tools to come.

Written by John Ankers

John Ankers

Writer

A former researcher in systems biology, John is now an online biology tutor and professional coach supporting the wellbeing of scientists and NHS professionals. He's writing, too, of course.

Website

• Video from work by Helen Farrants and colleagues
• Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
• Video originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in Nature Methods, September 2024