The copper-free click chemistry worked with three separate fluorophores, enabling the researchers to make two-to five-day-old zebrafish cells glow red, green and even near infrared, which is invisible to the eye but can be detected by some microscopes. They were able to observe differences over time in when and where on a single cell the sugar appeared, sugar movement through the cell interior, and in which tissues the sugar showed up.
"We're hoping to extend the technique to other sugars, too," Baskin said, noting that of the nine sugars used by vertebrates to build carbohydrates, Bertozzi's lab has found artificial surrogates for four of them. "We also want to try getting (artificial sugar) to work in different organisms and different disease models, such as cancer models in mice. Basically, we are providing this as a tool for the general community to use."
Amacher, who studies tissue patterning in the very early zebrafish embryo, is anxious to work with the labeling technique, but is waiting until Bertozzi's group gets it to work in hours-old embryos, at a stage when muscles and organs begin to form.
"Once they get the labeling technique to work at very early times, it is going to be an even more exciting collaboration, and hopefully, a continuing one," she said.
|Contact: Robert Sanders|
University of California - Berkeley