Coral Harvest Yields Fluorescent Light Switch

Courtesy of Atsushi Miyawaki

A group of researchers at RIKEN in Japan have developed a fluorescent protein that can be switched on and off more than 100 times.¹ Atsushi Miyawaki and colleagues engineered monomeric fluorescent protein 22Gm3 (renamed "Dronpa") from the coral Pectiniidae and found that strong irradiation at 488 nm converts it to a nonfluorescent state absorbing at 390 nm. This darkened protein can be switched back to its original emission state by irradiation for several minutes at 405 nm.

Fluorescent protein-labeling techniques previously were irreversible, precluding repeated measurements of a protein's behavior. Now by highlighting molecules, tracking their motions, clearing their fluorescence and repeating the experiment, "you can see if you have the same movement pattern emerging over time, [and] know if the movement pathways are stable or constantly changing," explains Jennifer Lippincott-Schwartz of the National Institutes of Health, who did not participate in this study....