Current Members

Our Principal Investigator

Prof. Frances Arnold

Linus Pauling Professor of Chemical Engineering, Bioengineering, and Biochemistry
Director of the Donna and Benjamin M. Rosen Bioengineering Center
2018 Nobel Laureate in Chemistry

B.S. Princeton University
Ph.D. University of California-Berkeley

Frances has spent her life convincing enzymes to do interesting and useful things through directed evolution, a process of iterative mutagenesis and screening. Outside of the lab she keeps very busy, enjoying yoga, gardening, hiking, and cooking.

Hometown: Pittsburgh, Pennsylvania (USA)

Our Laboratory Staff

Sabine Brinkmann-Chen, Ph.D.

Laboratory Manager

M.S. in Biology Saarland University
Ph.D. in Applied Microbiology, Saarland University

Sabine is the lab manager and staff scientist of the Arnold lab with a background in microbiology. She has been with the lab since October 2006. Outside of lab, she enjoys calisthenics training and Pilates.

Hometown: Saarbrücken, Germany

Cheryl Nakashima

Administrative Assistant

B.S., Wossamotta U.

Cheryl is the backbone of the Arnold Lab, and we don’t know what we would do without her. When she’s not organizing, she loves to create, collect and imagine all things art. A fun fact about Cheryl is that she loves the Denver Broncos, when they’re losing.

Hometown: San Jose, CA (USA)

Our Postdoctoral Fellows

Edwin Alfonzo, Ph.D.

NIH Ruth L. Kirschstein NRSA Postdoctoral Fellow

B.S. in Chemistry, University of Massachusetts Lowell
Ph.D. in Chemistry, Boston University

Edwin’s doctoral studies involved the total synthesis of Lignan natural products and the development of new photoredox catalysts for their application thereof. When not in the lab, Edwin enjoys dancing, cooking, and cheering on all Boston teams.

Hometown: Lawrence, MA (USA)

Soumitra Athavale, Ph.D.

B.S./M.S. in Chemistry and Biology, Indian Institute of Science Education and Research (IISER) Pune
Ph.D. in Chemistry, University of Illinois-Urbana Champaign

Soumitra’s Doctoral research in the Scott E. Denmark group focused on organic synthesis and elucidation of mechanistic pathways in asymmetric autocatalytic reactions. His research interests are in organic synthesis, biocatalysis and molecular evolution. As a postdoc in the Arnold lab, Soumitra is interested in harnessing the catalytic potential of iron enzymes to push the frontiers of synthetic methodology as well as to gain a fundamental mechanistic understanding of this enzymatic process. Outside the lab, Soumitra enjoys reading, music and solving synthetic chemistry puzzles.

Hometown: Pune, India

Anuvab Das, Ph.D.

B.Sc. in Chemistry, Presidency College (Calcutta University)
M. Sc. in Chemistry, Indian Institute of Technology Kharagpur 
Ph.D. in Chemistry, Texas A&M University

Anuvab’s graduate work in Dave Powers’ lab focussed on the structural characterization of reactive intermediates involved during nitrene transfer catalysis using photocdrystallography. After completing his Ph.D., Anuvab joined the Arnold lab as a postdoc, to learn about biocatalysis and molecular biology techniques. He is interested in developing novel C–H activation reactions using directed evolution of enzymes. Outside of lab, Anuvab enjoys playing video games, badminton and exploring U.S National parks.

Hometown: Kolkata, India

Julie Ducharme, Ph.D.

FRQNT Postdoctoral Fellow

B.S. in Food Science, McGill University
Ph.D. in Chemistry, McGill University

During her graduate degree, Julie studied the allosteric properties of the important drug-metabolizing enzyme, cytochrome P450 3A4. She developed a strong interest in protein structure-function relationships, protein dynamics, and allostery. She joined the Arnold group to deepen her knowledge in protein engineering strategies and develop novel biocatalysts for industrial purposes. Outside the lab, Julie enjoys music, swimming, doing yoga, and dinner with friends.

Hometown: Montreal, QB (Canada)

Tyler Fulton, Ph.D.

B.S. /M.S. in Chemistry, Bucknell University
Ph.D. in Chemistry, California Institute of Technology

Tyler’s doctoral studies in the lab of Prof. Brian Stoltz involved the total synthesis of natural products and the development of new methods for acyclic stereocontrol. When not in the lab, Tyler enjoys gardening, cooking, and going for hikes.

Hometown: Freeland, PA (USA)

Cooper Jamieson, Ph.D.

NIH Ruth L. Kirschstein NRSA Postdoctoral Fellow

B.A. in Chemistry & Art, Lewis & Clark College
M.S./Ph.D. in Chemistry, University of California, Los Angeles

Cooper completed his doctoral research in the Kendall N. Houk and Yi Tang laboratories and focused on the discovery and characterization of enzyme-catalyzed pericyclic reactions in nature. During this time, he also worked as a computational chemist at Ro5 and assisted in the development of machine learning models for drug discovery. Now, Cooper is integrating machine learning into the directed evolution pipeline and leveraging hemoproteins to catalyze heteroatom-heteroatom bond-formation. Outside of the lab, Cooper enjoys surfing and painting.

Hometown: San Luis Obispo, CA (USA)

Jennifer Kennemur, Ph.D.

NIH Ruth L. Kirschstein NRSA Postdoctoral Fellow

B.S. in Chemistry, Texas Tech University
M.S. in Chemistry, University of Illinois, Urbana-Champaign
Ph.D. in Chemistry, Max-Planck-Institut für Kohlenforschung

Jenni conducted her PhD studies in Ben List’s group at the MPI für Kohlenforschung in Germany, where she developed extremely acidic chiral organocatalysts for applications in a myriad of asymmetric transformations. Inspired by the remarkable ability of enzymes to impart regio- and stereoselectivity, Jenni moved to the Arnold group to learn how to use protein engineering techniques to develop new-to-nature transformations. Outside of the lab, Jenni enjoys exploring LA’s prolific stand-up comedy scene and figuring out new ways to live a more sustainable, low-waste life.

Hometown: Grand Prairie, TX (USA)

Zhen Liu, Ph.D.

B.S. in Chemistry, Peking University
Ph.D. in Chemistry, The Scripps Research Institute

Zhen earned his Ph.D. degree from The Scripps Research Institute, studying transition metal-catalyzed alkene and alkyne functionalization. He is currently a Postdoctoral Fellow in the Arnold lab, working on biocatalytic carbene and nitrene transformations. Outside of the lab, Zhen enjoys playing basketball, watching sports games, and watching anime.

Hometown: Xuzhou, Jiangsu (China)

Runze Mao, Ph.D.

SNF Postdoctoral Fellow

B.S.  in Chemistry, Henan Normal University
M.S. in Chemical Biology, Peking University 
Ph.D. in Chemistry, EPFL

Runze has a broad interest in catalysis and has been working on developing novel catalytic approaches for chemical transformations related to synthesis, chemical biology and sustainability. After realizing the power of biocatalysis, he joined the Arnold lab, where he focuses on exploring the vast potential of biocatalysis and using it to solve synthetic challenges. Outside of the lab, Runze enjoys hiking, playing basketball, and swimming.

Hometown: Xinxiang, Henan (China)


Nicholas Porter, Ph.D.

Helen Hay Whitney Postdoctoral Fellow

B.A. in Chemistry, Boston University
Ph.D. in Chemistry, University of Pennsylvania

Throughout his research career, Nick has maintained an interest in the structure-function relationships that underpin enzyme function. In the Arnold Lab, he works on projects related to enzymatic carbene transfer and eliciting new chemistry from metalloenzymes. Outside of the lab, he enjoys climbing, hiking, cooking, reading, and board games of any kind.

Hometown: Shrewsbury, Massachusetts (USA)

Doris Taylor, Ph.D.

Presidential Postdoctoral Fellow

B.S. in Biochemistry & Molecular Biology, University of Baltimore County
Ph.D. in Biochemistry & Molecular Biology, Baylor College of Medicine

In graduate school, Doris studied the mechanism and inhibition of β-lactamases (which mediate antibiotic resistance) to help find new inhibitors that could serve as antibacterial agents. Doris is interested in engineering enzymes for unique reactions as well as learning how to facilitate this process with machine learning. Outside of lab Doris enjoys watching anime and Marvel shows/movies, reading Black fantasy/sci-fi, trying new foods, and traveling.

Hometown: PG County, MD (USA)

Our Graduate Students

Patrick Almhjell, G5

Biochemistry and Molecular Biophysics

B.S. in Medicinal Biochemistry, Arizona State University

During his undergraduate, Patrick used Rosetta to design self-assembling metalloproteins that contained noncanonical amino acids (ncAAs). Unwilling to stop working with ncAAs, he now works in the Arnold Lab to engineer enzymes that synthesize these molecules in a simple and sustainable manner. Patrick’s love of ncAAs is matched only by his love of the outdoors, where he enjoys climbing, snowboarding, and camping.

Hometown: Phoenix, Arizona (USA)


Shilong (Gregg) Gao, G4


B.A. in Biochemistry and Molecular Biology,  Boston University

During his undergrad, Shilong worked on natural product synthesis and re-modification. In the Arnold lab, he is currently working on nitrogen-transfer reactions. Shilong enjoys weight-lifting, playing guitar, and video games.

Hometown: Beijing, China

Kadina Johnston, G4

NIH Biotechnology Leadership Training Program
Amazon AI4Science Fellow

B.S. in Biomedical Engineering and Chemistry, University of Wisconsin-Madison

During undergrad, Kadina studied Sis1, engineered biosensors at Promega, and later designed nanoparticles for drug delivery. Currently she is a part of the ML subgroup and works on developing ML-based methods for directed evolution. Outside of the lab Kadina enjoys surfing, hiking, and climbing.

Hometown: Summit, Wisconsin (USA)

Francesca-Zhoufan Li, G2


B.S. in Bioengineering and B.S. in Chemical Biology, University of California-Berkeley

Before joining the Arnold Lab, Francesca worked on a wide range of synthetic biology and protein engineering projects. Currently, she is a part of the ML subgroup. Outside of the lab, Francesca is active in DEI advocacy and enjoys staying active especially outdoors, puzzles (giant jigsaw and killer Sudokus), and iPhoneography.


Ravi Lal, G3

Chemical Engineering

B.S. in Chemical Engineering, University of California-Berkeley

During undergrad, Ravi performed research in the Keasling lab, investigating domain swapping in modular type I polyketide synthases. He is currently using directed evolution methods to bring novel reactivities to the growing family of carbene transferase enzymes. In his free time Ravi enjoys watching basketball, hiking, and trying to find East coast quality pizza on the West coast.

Hometown: Ithaca, New York (USA)

Yueming Long, G1


B.S. Medicinal Chemistry, Wake Forest University

Yueming studied small gasotransmitter molecules in her undergrad and developed several novel compounds with antibacterial effects. Currently she is working on discovering new  metalloenzyme activities. Outside of lab, Yueming likes to cook and make glass beads.

Hometown: Shanghai, China


Ryen O’Meara, G1

Chemical Engineering

B.S.E. in Chemical Engineering, University of Michigan-Ann Arbor

During undergrad, Ryen aided in the development of a novel discovery platform for agonist antibodies and applied it to the T cell receptor OX40. In the Arnold lab, he engineers enzymes to degrade emerging environmental contaminants. Outside of research, Ryen loves all forms of physical movement and wellness, cooking, baking bread, and reading literature.

Hometown: Canton, Michigan (USA)


Ziyang (Nick) Qin, G2


B.S. in Chemistry, University of Science and Technology of China

During his undergrad, Ziyang conducted research on both transition-metal catalysis and main-group catalysis. Being amazed by biocatalysis, he came to Caltech and joined the Arnold lab trying to develop novel transformations using engineered proteins. Outside the lab, Ziyang enjoys traveling, hiking, absorbing in art museums, hunting for delicious food.

Hometown: Chongqing, China


Nicholas Sarai, G4

Biochemistry and Molecular Biophysics
NIH Biotechnology Leadership Training Program

B.S. in Biochemistry, University of Denver

After undergraduate research in organic synthesis and molecular biology, Nicholas spent two years at the National Renewable Energy Laboratory focused on thermophilic enzymology and metabolic engineering. Currently he is engineering enzymes to degrade recalcitrant compounds. Nicholas devotes his time outside of lab to skiing and climbing.

Hometown: Saint Louis, Missouri (USA)


Daniel Wackelin, G4

Chemical Engineering

B.S.E. in Chemical and Biomolecular Engineering, University of Connecticut

During undergrad, Daniel studied yeast surface display of proteins and improved mammalian cell expression of antibody derivatives. Now, he works on engineering carbene transferases to perform new-to-nature reactions. When not in lab he enjoys hiking, camping, and board games with friends.

Hometown: Farmington, Connecticut (USA)

Jason Yang, G1

Chemical Engineering

B.S. in Chemical Engineering, Yale University

Jason studied materials for membrane separations using experiments, simulations, and machine learning during undergrad. He is now working in the ML subgroup to develop computational approaches to facilitate protein engineering. Outside of the lab, Jason enjoys electronic music, exploring new restaurants, and attempting to get better at beach volleyball.

Hometown: Wilmette, Illinois (USA)


Our Undergraduates and Visitors

Catherine Ko

Undergraduate Researcher – Chemistry

Catherine (’24) studies chemistry and biology at Caltech and has been part of the Arnold Lab since her freshman year. She has worked on stabilizing and promoting the evolution of new-to-nature biocatalysts. Through the Arnold Lab, she has gained hands-on experience with both the biological and chemical aspects of her projects. Beyond her studies and research, Catherine likes taking pictures, drawing/painting, playing badminton with friends, and planning enriching student life events through the Caltech Y.

Hometown: San Francisco, California (USA)

Grace Liu

Undergraduate Researcher – Bioengineering

Grace is an undergraduate student majoring in bioengineering at Caltech. Her research involves using machine learning to analyze protein data. Outside of school and research, she enjoys writing, skiing and watching musicals.

Hometown: Toronto, Canada

Sophia Wu

Undergraduate Researcher – Bioengineering

Sophia is an undergraduate student at Caltech (’25) majoring in bioengineering. Her research explores the evolution of novel biocatalysts to perform chemical transformations. Through biocatalysis, she hopes to solve synthetic challenges. Outside of lab, Sophia is involved in Caltech’s Fluid & Dynamics a cappella group. She enjoys karaoke and playing the cello and piano.

Hometown: Boston, Massachusetts (USA)