Leica TauSTED allows multicolor imaging of cells at nanoscale

13 Mar 2024

Improvements to STED platform combine spatial and fluorescence lifetime information for fuller picture of cell dynamics.

Leica Microsystems has unveiled TauSTED Xtend, a development of the company's TauSTED super-resolution platform intended to allow multicolor live cell imaging at nanoscale resolution.

The platform allows researchers to directly monitor fast biological processes on-the-fly, according to the company.

"TauSTED Xtend ensures that live cell experiments can be carried out over a longer time span thanks to the balance of light exposure and resolution which leads to gentler imaging at stunning nanoscale depths," commented James O’Brien from Leica Microsystems. "Researchers can now reveal the invisible in unexplored areas of research."

The principles behind stimulated emission depletion (STED) microscopy were established three decades ago, when researchers working on fluorescence microscopy discovered that following up the initial stimulating laser pulse with a second pulse in a ring-shaped profile could narrow the area of detectable fluorescence down to a smaller spot than conventional techniques can optically isolate.

Several enhancements to the technique have been made since then, including further modifications to the light pulses and the creation of new fluorescent markers tailored specifically to the process. The developers of STED shared the 2014 Nobel prize for chemistry in recognition of the technique's impact.

Leica designed TauSTED in 2019 as "a new approach to STED super-resolution to deliver high quality, multicolor STED in two and three dimensions, compatible at the same time with live-cell imaging of highly dynamic processes."

According to product literature, TauSTED combines the optical signals from STED with the physical information from fluorescence lifetime measurements, the latter acquired at typical confocal speeds. This approach "uses phasor analysis in a novel way and works in an automated manner, enabling increased STED resolution and elimination of uncorrelated background noise even at low excitation and STED light dose."

Incorporate STED in workflows more easily

The company has now developed the principle further with TauSTED Xtend, enabling extended multicolor imaging of live and intact specimens.

"TauSTED Xtend offers new opportunities for single-and multicolor experiments using green fluorescent proteins and fluorophores that are a workhorse in life science research and currently underused in studies at the nanoscopic level," said Ulf Schwarz from Leica.

The company's intention is that TauSTED can now be incorporated into common lab workflows more easily, allowing clinicians to enhance their existing preferred imaging protocols with super-resolution STED capabilities. It pointed in particular to use of TauSTED alongside the company's Stellaris Falcon fluorescence lifetime imaging microscope, designed to follow fast molecular interactions.

This instrumental combination can expand the palette of fluorophores suitable for a given imaging investigation, according to Leica, by allowing additional fluorescent dyes to be used separately or together in new combinations, so as to reinforce experimental design.

"Scientists can now effectively scale their experiment down to the nanoscale using familiar protocols and a wide range of fluorescent labels and markers commonly used in biological research," commented Ulf Schwarz.