Professor Ellen Sletten’s research is featured in a recent ACS Central Science article and corresponding first reactions piece honoring her as “an inspiring role model in the central science of chemistry”.
The Sletten Group recently published a paper about new water-soluble dyes for imaging through tissue (ACS. Cent. Sci. 2025, 11, 208-218). Fluorescence imaging allows visualization of individual molecules within living organisms, but traditional dyes face challenges, such as the scattering of visible light by biological tissues, which complicates imaging. Scientists have turned to the short-wave infrared (SWIR) region, where light penetrates tissues more effectively, avoiding issues like water and hemoglobin absorption. However, these fluorophores often suffer from poor solubility, brightness, and stability.
In the Sletten Group’s most recent work, led by graduate student Emily Mobley, many of the previous limitations in solubility, brightness, and protein interactions are overcome. The key innovation is the development of “CStar” dyes, which involve attaching polymer chains to fluorophores, shielding them from albumin binding and improving their performance in living animals. These new dyes allow for clearer, more accurate imaging of biological systems, enabling the tracking of dynamic processes within intact organisms. The work represents a significant step forward in fluorescence imaging, offering a path toward multicolor imaging in live animals and advancing both basic biological research and medical applications.
The article was accompanied by a first reaction piece titled “Stars by the Pocketful” by Luke D. Lavis and his daughter Clara E. Lavis (ACS Cent. Sci. 2025, 11, 183−186) which intertwined with a Taylor Swift theme discusses advancements in fluorescence imaging. The article highlights a series of innovations in fluorescent dyes, particularly those developed by the Sletten lab, which make them more suitable for in vivo applications. The article concludes with the following note: “Professor Ellen Sletten is an inspiring role model in the central science of chemistry, so I asked my daughter Clara (age 11) to help write this First Reactions piece. And we took inspiration from another female icon at the top of her field.”
Sletten earned her Bachelor of Arts in Chemistry from Stonehill College in 2006. She then pursued her Ph.D. at the University of California, Berkeley, under the mentorship of Nobel Laureate Professor Carolyn Bertozzi. Following her Ph.D., Sletten undertook postdoctoral research MIT with Professor Timothy Swager. Her postdoctoral work included the development of innovative materials for biomedical applications, which would later influence her research at UCLA. Since joining the faculty at UCLA in 2015, Sletten has established a vibrant and productive research group. She focuses on the development of chemical tools to study and manipulate biological systems in real-time, with applications in imaging, diagnostics, and therapeutics.
“Ellen’s brilliant research, her teaching and development of courses and curricula, and her willingness to take on departmental responsibilities, have led to a major expansion of chemical biology at UCLA, to everyone’s benefit” said Professor Ken Houk, one of her senior colleagues and collaborators in the department.
Sletten’s contributions to the field have been widely recognized. Among these are the Helmholtz High Impact Award (2024), the UCLA Distinguished Teaching Award (2023), the ACS Women’s Chemist Committee Rising Star Award (2023), the Agnes Fay Morgan Research Award (Iota Sigma Pi) (2022), and the department’s 2020-2021 McCoy Award, in recognition of her greatest contribution of the year to the science of chemistry and biochemistry.
