Lisa Racki

Associate Professor, Department of Integrative Structural and Computational Biology

lracki(at)scripps.edu, 858-784-2674 (Office)

I obtained a BA in Biochemical Sciences at Harvard and wrote my honors undergraduate thesis in Fred Ausubel’s lab, where I used classical genetic approaches to study the innate immune response of plants (Arabidopsis thaliana) to bacterial pathogens (Pseudomonads). I then obtained my PhD in Biochemistry and Molecular Biology under the mentorship of Geeta Narlikar at UCSF, where I studied eukaryotic ATP-dependent chromatin remodeling enzymes. At the end of graduate school, I wanted to combine my interests in bacterial pathogens and enzymology. I became fascinated with the work of the late great biochemist Arthur Kornberg, who in the latter part of his career, studied bacterial polyphosphate kinases, enzymes bacteria use to make an inorganic polymer of phosphoryl groups (polyP) from ATP. PolyP synthesis is both evolutionarily ancient, and important for virulence in many clinically important human pathogens. As a postdoc under the mentorship of Dianne Newman at Caltech, I studied how bacterial polyP contributes to fitness during nutrient limitation in the opportunistic pathogen, Pseudomonas aeruginosa. The polyP polymer forms membraneless compartments in the nucleoid region of many bacterial cells, and my lab is currently exploring the structural and functional relationship between this primordial inorganic polymer and bacterial chromatin. The broader goal of my lab is to find novel ways to target bacteria in growth-arrested states, when they are intrinsically more tolerant to conventional antibiotics. Members of my lab study chromatin structure and function from the molecular to cellular scale, using a variety of quantitative biochemical, biophysical, and cell biological techniques. My lab is also developing phage-based tools to study bacterial chromatin in single cells. I am grateful for having truly exceptional mentors and collaborators throughout my journey in science. My favorite part of being a PI is the privilege of working with and learning from trainees and collaborators at all stages of their careers.

My current favorite activity outside of the lab is gardening with my family.

Julia Polay

Lab Admin Coordinator, jpolay(at)scripps.edu

858-784-8760 (Office)

While my own background stems from an education and career outside of the sciences, I have spent the better part of the last decade surrounded by chemists. My previous experiences have demanded acute organization, clear communication, and an eye for detail. Nothing gives me more fulfillment than supporting a team of great minds and helping them achieve results.

Tanxi Bai

Postdoctoral Associate, tbai(at)scripps.edu

Tanxi received her B.S in Biology from Beijing Normal University in 2014. After that, she received her Ph.D. in Biology from Bryan Wei's lab at Tsinghua University in 2020, focusing on DNA architecture design and application. With a deeper understanding of nucleic acids as building materials, she would like to dig into their mysteries in living systems and study their molecular architecture and interactions.

She enjoys discovering new dining spots and food. Besides swimming, she is willing to learn diving and surfing.

Constanza PaZ Torres-Paris

Posdoctoral Associate, cpaz@scripps.edu

Connie received her BS in Molecular Biotechnology Engineering from the University of Chile in 2015, where she worked at Carlos Jerez’s lab studying the exopolyphosphatases of extremophiles. She received her PhD in Biochemistry and Molecular Biophysics from the University of California San Diego in 2023, where she worked in the lab of Elizabeth Komives studying how the dynamics of a serine protease tuned its activity. In the Racki lab, she aims to bridge her microbiology and biophysics training to study polyphosphates of P. aeruginosa. Outside of the lab, she enjoys experimenting with new cooking recipes and biking around the city.

Nick Tu

Graduate Student, nicholastu(at)scripps.edu

Nick is a San Diego native, completing K-12 there and receiving his B.S. in Biochemistry/Chemistry from UC San Diego in 2019. Afterwards, he worked as a research assistant at Hologic under the R&D team developing nucleic acid tests for pathogens including SARS-CoV-2. He is interested in the molecular interactions of polyphosphate with AlgP from P. aeruginosa. Outside of the lab, Nick enjoys playing Magic the Gathering, hanging out with his dog-children Emma and Rosie, and taking long walks on the beach-adjacent campus.

Joseph Agha

Research Technician, jagha(at)scripps.edu

I received my BS in biochemistry and molecular biology from UC Irvine in 2023. Previously I was an undergraduate researcher in the Wiles lab at UC Irvine. In the Wiles lab, I studied the role of bacteriophage in interbacterial competition. I am eager to explore new topics in molecular and microbiology. My long-term goal is to pursue a graduate degree. In my free time, I enjoy playing video games and trying new sports.

JoRDAN BEACH

Research Technician, jbeach(at)scripps.edu

Jordan earned her B.S. in Microbiology from UC Santa Barbara in 2025. As an undergraduate researcher in the Rothman Lab, she investigated tardigrade locomotion and resilience, contributing to the development of an AI training database that tracked key features of tardigrade movement. She is currently looking to expand her experience in microbiology through hands-on wet lab techniques, including microbial imaging, culturing, and testing—particularly with Pseudomonas species and their ability to grow and survive in different environmental conditions. Jordan ultimately plans to pursue a Master’s or Ph.D. in Microbiology. Outside the lab, she enjoys going to the beach, reading mystery novels, running, and practicing yoga.

Madeline Ammend

Research Assistant, mammend(at)scripps.edu

Maddie received her BS in Biology from the University of St. Thomas in Saint Paul, Minnesota in 2021, where she studied sustainable agriculture. In her final semester, she took a microbiology course and learned that bacteria are way cooler than plants. Her quest to understand how bacteria shape the world around us led her to accidentally wander into the laboratory of Dr. Daniel Bond at the University of Minnesota. Here, she spent the next two years studying extracellular electron transfer in Geobacter sulfurreducens, pondering the mysteries of the Nernst Equation, and earning her MS in Microbial Engineering. In the Racki Lab, she hopes to investigate the fantastic metabolic versatility of Pseudomonas aeruginosa, particularly the role of polyP in helping cells survive under starvation conditions. In her free time, she can be found going for absurdly long walks with a film camera, making pottery, rock climbing, peering into tidepools, and snuggling with her cats, Edmund and Fitzgerald.

Monarch

@monarch_the_papillon

Racki Lab Alumni

Former Postdocs 

        
          Last Name
          First Name
          Current Status
           Location
        
Si
        Fangwei
        Assistant Professor
        Carnegie Mellon, Dept.  of Physics 
        
Chawla
        Ravi
        CEO and Founder
        ChakraTech 
        





Former Staff 

        
          Last Name
          First Name
          Racki Lab Role
          Current Status
          Location
        
Habel
        Amanda
        Research Assistant 
        Associate Scientist
        AnaptysBio
        
Parmar
        Dhruv
        Research Technician
        Laboratory Assistant
        UCSD
        
Cobb
        Polina
        Research Technician
        Graduate Student
        Scripps Research
        


Former Interns 

        
          Last Name
          First Name
          Racki Lab Role
          Current Status
          Location
        
Fallon
        Michael
        SURF Student 
        Undergraduate
        Williams College
        


Rotation Students 

        
          Last Name
          First Name
          Scripps Lab
        
LeBlanc
        Gabrielle
        Constantinides Lab
        
Sattler
        Rachel
        de la Torre Lab, Chanda Lab (Joint)
        
Chang
        Atty (Ya-Ting))
        Grotjahn Lab
        
Li
        Catherine
        Ken Lab
        
Koide
        Yukiye
        Law Lab
        
Shu
        Siyi
        Jardine Lab
        