Roger Y. Tsien

In 2016, a new class of fluorescent protein was evolved from a cyanobacterial (Trichodesmium erythraeum) phycobiliprotein, α-allophycocyanin, and named small ultra red fluorescent protein (smURFP). smURFP autocatalytically self-incorporates the chromophore biliverdin without the need of an external protein, known as a lyase. Jellyfish- and coral-derived fluorescent proteins require oxygen and produce a stoichiometric amount of hydrogen peroxide upon chromophore formation. smURFP does not require oxygen or produce hydrogen peroxide and uses the chromophore, biliverdin. smURFP has a large extinction coefficient (180,000 M cm) and has a modest quantum yield (0.20), which makes it comparable biophysical brightness to eGFP and ~2-fold brighter than most red or far-red fluorescent proteins derived from coral. smURFP spectral properties are similar to the organic dye Cy5.

Tsien died on August 24, 2016. Although the specific cause of death was not disclosed, it was reported that he died while on a bike trail in Eugene, Oregon. Prior to his death, Tsien had survived cancer and suffered a stroke in 2013.

Tsien was also a notable biochemical inventor and holds or co-holds about 100 patents till 2010. In 1996, Tsien co-founded the Aurora Biosciences Corporation, which went public in 1997. In 2001, Aurora was acquired by the Vertex Pharmaceuticals. Similarly, Tsien was also a scientific co-founder of Senomyx in 1999.

In 2009, a new kind of Infrared Fluorescent Protein (IFP) was developed by Tsien's group, and further reported and described by Science. The new IFPs are developed from bacterial phytochromes instead of from multicellular organism like jellyfish. Under normal conditions, bacterial phytochromes absorb light for signaling instead of fluorescence, but they can be turned fluorescent after deleting some of the signaling parts by genetic means such as site-directed mutagenesis. In order to fluoresce, IFPs require an exogenous chromophore, biliverdin.

In 2008, Tsien shared the Nobel Prize in Chemistry with Osamu Shimomura and Martin Chalfie for "the green fluorescent protein: discovery, expression and development."

In 2004, Tsien was awarded the Wolf Prize in Medicine "for his seminal contribution to the design and biological application of novel fluorescent and photolabile molecules to analyze and perturb cell signal transduction."

FlAsH-EDT2 is a biochemical method for specific covalent labeling inside live cells. It's a method based on recombinant protein molecules, and was developed by Tsien and his colleagues in 1998.

Since the discovery of the wild type GFP, numerous different mutants of GFP have been engineered and tested. The first significant leap forward was a single point mutation (S65T) reported by Tsien in 1995 in Nature. This mutation dramatically improved the fluorescent (both intensity and photostability) and spectral characteristics of GFP. A shift of the major excitation peak to 488 nm with the emission peak staying at 509 nm thus can be clearly observed, which matched very well the spectral characteristics of commonly available FITC facilities. All these then largely amplified the practicality of using GFP by scientists in their research. Tsien mainly contributed to much of our understanding of how GFP works and for developing new techniques and mutants of GFP.

Roger Tsien had built the foundation of next generation sequencing technology that is widely used today. On 26 October 1990, Roger Tsien et al filed a patent of stepwise ("base-by-base") sequencing with removable 3' blockers on DNA arrays. Illumina integrated this concept with DNA cloning for their next generation sequencer.

Tsien was a pioneer of calcium imaging and known for developing various dyes which become fluorescent in the presence of particular ions such as calcium. One such dye, Fura-2, is widely used to track the movement of calcium within cells. Indo-1, another popular calcium indicator, was also developed by Tsien's group in 1985. He has also developed fluorescent indicators for other ions such as magnesium, zinc, copper, iron, lead, cadmium, aluminum, nickel, cobalt, and mercury.

After completing his bachelor's degree, Tsien joined the Physiological Laboratory at the University of Cambridge in Cambridge, England with the aid of a Marshall Scholarship, and resided at Churchill College, Cambridge. He received his Ph.D. in physiology in 1977 for research on The Design and Use of Organic Chemical Tools in Cellular Physiology formally supervised by Richard Adrian in the Department of Physiology and assisted by Andy Holmes, Gerry Smith and Jeremy Sanders in the Department of Chemistry.

Following his Ph.D., Tsien was a Research Fellow at Gonville and Caius College, Cambridge from 1977 to 1981. He was appointed to the faculty at the University of California, Berkeley, from 1982 to 1989. Beginning in 1989, he worked at the University of California, San Diego, as Professor of Pharmacology and Professor of Chemistry and Biochemistry, and as an investigator of the Howard Hughes Medical Institute.

Tsien attended Harvard College on a National Merit Scholarship, where he was elected to Phi Beta Kappa as a junior. He graduated summa cum laude with a Bachelor of Arts in chemistry and physics in 1972. According to his freshman-year roommate, economist and Iowa politician Herman Quirmbach, "It's probably not an exaggeration to say he's the smartest person I ever met ... [a]nd I have met a lot of brilliant people."

Roger Yonchien Tsien (Chinese: 錢永健 ; February 1, 1952 – August 24, 2016) was an American biochemist. He was a professor of chemistry and biochemistry at the University of California, San Diego and was awarded the Nobel Prize in Chemistry for his discovery and development of the green fluorescent protein, in collaboration with organic chemist Osamu Shimomura and neurobiologist Martin Chalfie. Tsien was also a pioneer of calcium imaging.

Tsien was born to a Chinese American family in New York, in 1952. He grew up in Livingston, New Jersey and attended Livingston High School. Tsien traces his family ancestry to Hangzhou, China. His father Hsue-Chu Tsien, an MIT and Shanghai Jiao Tong University alumnus, was a mechanical engineer and had excelled academically, graduating at the top of his university class.