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)

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)

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)

Ziqi Li, Ph.D.

B.S. in Chemistry, Nankai University
Ph.D. in Chemistry, Scripps Research

Ziqi conducted her Ph.D. research with Prof. Keary M. Engle at Scripps Research, where she explored how ligand design, reagent development, and synergistic catalysis enable regio- and enantioselective alkene functionalization. As a postdoc in the Arnold lab, Ziqi is excited to unlock the biocatalysis territory for the development of selective, efficient, and sustainable synthetic methodologies. Outside the lab, Ziqi enjoys all kinds of natural fragrances, coffee and tea included.

Hometown: Heze, Shandong (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)


Ariane Mora, Ph.D.

Schmidt Science Fellow

B.E. in Electrical and Computer Engineering (Hons), The University of Queensland
Ph.D. in Bioinformatics, The University of Queensland

During her PhD Ariane developed generative models of epigenetics in development and disease. She is excited to be part of the multi-disciplinary Arnold team and aims to engineer enzymes to tackle environmental issues. In her spare time Ariane enjoys bird watching, oil painting, and rock climbing.

Hometown: Brisbane (Australia)

Julia Reisenbauer, Ph.D.

SNSF Postdoctoral Fellow

B.Sc. in Chemistry, ETH Zurich
M.Sc. in Chemistry, ETH Zurich
Ph.D. in Chemistry, ETH Zurich

Julia dedicated her doctoral years to advancing the field of nickel-catalyzed transfer hydrocyanation reactions under the guidance of Prof. Bill Morandi at ETH Zurich. Simultaneously, she actively contributed to the development of innovative skeletal editing strategies for N-heterocycles. After obtaining her Ph.D., Julia became a postdoctoral researcher in the Arnold lab, where she embarked on a journey to gain expertise in biocatalysis and molecular biology techniques. Beyond her research pursuits, you’ll often spot her outdoors, indulging in her passions for biking, hiking, and bouldering.

Hometown: Edlitz (Austria)

Kathleen Sicinski, Ph.D.

NIH Ruth L. Kirschstein NRSA Postdoctoral Fellow

B.S. in Biochemistry, Moravian College
Ph.D. in Chemistry, Tufts University

Katie obtained her Ph.D. at Tufts University under the advisement of Prof. Krishna Kumar. Her doctoral work focused on chemical strategies to increase protease stability of peptide hormones for the treatment of non-communicable diseases such as type II diabetes, obesity, and Alzheimer’s disease. Now in the Arnold laboratory, Katie is harnessing the power of enzymes and directed evolution to engineer biocatalysts for chemical transformations that are hard to achieve by traditional synthetic methods. When not in the laboratory, you can find Katie teaching yoga, on the dance floor, or spending time with her four nieces and six nephews.

Hometown: Allentown, PA (USA)

Ziyan Zhang, Ph.D.

B.S. in Chemistry, Beijing Technology and Business University
Ph.D.  in Chemistry, The University of Texas at Dallas

Ziyan obtained her Ph.D. at The University of Texas at Dallas under the guidance of Prof. Vladimir Gevorgyan. During her doctoral studies, she focused on the development of denitrogenative transformations of pyridotriazoles and photoinduced palladium hydride-catalyzed reactions. Currently, as a postdoc in the Arnold laboratory, Ziyan is unlocking the power of enzymes and directed evolution for developing new-to-nature transformations. Outside of the lab, Ziyan enjoys reading, cooking, and hiking.

Hometown: Heze, Shandong (China)

Our Graduate Students

Mikhail Hameedi, G2

Biochemistry and Molecular Biophysics

BSc. Biochemistry from Imperial College, London
MPhil in Biological Sciences from the University of Cambridge

During undergrad, Mikhail structurally and functionally characterized bioenergetic enzymes before doing the same for mitochondrial complex I during his masters. Following 2 years at Stanford/SLAC studying SARS-CoV-2 proteases, he started at Caltech to study how Machine Learning can be applied to the directed evolution of enzymes. Outside the lab, Mikhail loves playing squash, art museums and the NHL.

Hometown: London, England (U.K.)

Deirdre Hanley, G2


University of California-Berkeley

During her undergraduate studies, Deirdre utilized artificial metalloenzymes and FRET techniques to develop ratiometric protein-based oxygen sensors. Following her work on protein functionality, she joined Caltech to employ directed evolution in the search for novel enzyme functions. In her free time, Deirdre enjoys hiking, collecting houseplants, and exploring SoCal.

Hometown: San Francisco, CA

Ravi Lal, G5

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)

Francesca-Zhoufan Li, G4


Amazon AI4Science Fellow

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.


Yueming Long, G3


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


Ryen O’Meara, G3

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, G4


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


Jason Yang, G3

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

Emre Guersoy, Master

Visiting M.S. Student – Biotechnology

MSc in Biotechnology, ETH Zürich

BSc in Biology, ETH Zürich

After undergrad, Emre undertook a 6-month internship in strain engineering to increase ABS production. During his Master’s degree, he conducted a research project on lab automation and engineering. Currently, he joined the Arnold group to apply machine learning for protein engineering. In his free time, Emre enjoys playing soccer, hiking, and is currently trying to learn how to surf.

Hometown: Olten, Switzerland

Severin Stalter, Master

Visiting M.S. Student

M.S. in Chemical Biology, Karlsruhe Institute of Technology

B.S. in Chemical Biology, Karlsruhe Institute of Technology

During his undergrad, Severin worked on natural product synthesis and the derivatization of fatty acids as renewable monomer source. He joined the Arnold group as a Visiting Student Researcher as part of his M.S. degree program to perform new-to-nature biocatalysis. Outside the lab, Severin enjoys all types of sports and getting together with friends.

Hometown: Landau, Germany

Annika Viswesh, SURF

Undergraduate Researcher – Computer Science

Annika (’26) is an undergraduate student at Caltech majoring in Computer Science. As part of the ML subgroup, she works on using machine learning techniques to better predict protein fitness by utilizing structural data from MD simulations. Apart from her research and studies, Annika enjoys playing chamber music with her friends as a violinist and reading dystopian novels.

Hometown: Palo Alto, CA

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)

Ethan Lin, SURF

Undergraduate Researcher – Chemistry

Ethan is an undergraduate chemistry major at Caltech (class of 2026). He is interested in the intersection of biochemistry and organic chemistry. In his free time, Ethan enjoys cycling (including unicycling) and bird photography.

Hometown: San Diego, California (USA)

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)