Fluorescent dye enables longer bioimaging of single molecules

A group of chemists from Japan has developed a photostable fluorescent dye that enables long-term bioimaging of living cells in the near infrared region (NIR), according to a new study in Angewandte Chemie International Edition.

The dye—photo-resistant xanthene dye used at 710 nanometers (PREX 710)—was developed by teams from the Nagoya University, RIKEN research institute and Ehime University, all located in Japan.

"We were really excited to see that by using PREX 710, we could visualize live cell components for many minutes compared to only a few seconds that could be achieved with conventional dyes," said one leader of the study, Masayasu Taki, MD, with Nagoya University’s Institute of Transformative Bio-Molecules, in release.

In testing the dye’s ability, the team found 80 percent of the single molecule fluorescent signals emitted from PREX 710 could be detected in two minutes, while 50 percent of signals from Alexa Fluor 647—cyanine dye—were lost within 20 seconds. Thus, authors concluded PREX 710 to be beneficial for single molecule fluorescent imaging.

Researchers were also able to use PREX 710 in the three-dimensional (3D) deep in vivo imaging of blood vessels in mouse brains. The dye’s high photostability allowed for repeated imaging, and its unique light absorption and emission qualities paired with other fluorescent dyes enabled multicolor imaging.

“We were pleased to demonstrate that PREX 710 and its derivatives are useful tools for the investigation of the dynamics of living organisms, tissues, cells, and molecules," Taki said.

"We are currently working on developing other NIR fluorescence probes that could be used for staining specific proteins as well as examining live structures and processes in more depth. We hope that this will lead to the visualization and elucidation of various phenomena in living systems, including medical symptoms," he concluded.