Sarah Keller
University of Washington, WA·Biophysics
Each cell is wrapped in a membrane made largely of lipids, fat-like molecules. Like oil and vinegar, these lipids can separate into two coexisting liquid regions called phases.
- Fields
Biophysics
Chemistry
Physics
- Topics
lipid membranes
liquid-liquid phase separation
membrane demixing
- Grants
- 1 known grant, through Jun 2027
What they work on
- Test whether asymmetric lipid vesicles, membrane bubbles with different lipids in each layer like real cells, undergo liquid-liquid phase separation the same way as flat, taut membranes.
- Develop a new, more accessible method to measure lipid ratios in coexisting membrane phases, and analyze the lipid compositions of vesicles made by different preparation methods.
- Use Raman imaging, which identifies molecules by how they scatter light, to test theoretical predictions of how lipids are distributed across membrane phases and their boundaries.
- Use fluorescence microscopy to test theories about asymmetry in the number and type of lipids in vesicle membranes, and search for phase separation in previously untested lipid compositions.
More about the research
This process, called liquid-liquid phase separation or demixing, matters in living cells. For example, when a yeast cell runs low on nutrients, the membrane of its vacuole, a storage compartment, demixes. Understanding when and how membranes demix requires careful measurements on well-controlled artificial membranes.
Why it matters
This is basic science. It adds precise measurements of how lipid membranes separate into liquid phases, along with new methods and published code for measuring the composition of each phase. These data can be used to test theories and computer simulations of membranes, and could eventually inform understanding of how cell membranes reorganize, such as when yeast cells respond to nutrient limits.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
Atul Parikh
University of California-Davis, CA·Biophysics
Quantify how liquid droplets coarsen, growing and merging over time, during liquid-liquid phase separation confined inside giant vesicles, using fluorescence microscopy and quantitative image analysis.
Nathan Wittenberg
Lehigh University, PA·Biophysics·Early-career
Determine how vesicle size, surface charge, lipid saturation and lipopolysaccharide composition control binding of the antimicrobial peptide LL-37, using liposomes of defined composition measured on single vesicles and subpopulations.
Padmini Rangamani
University of California-San Diego, CA·Biophysics
Model how lipid and protein asymmetry across the plasma membrane sets whether it buds inward (endocytosis, the uptake of outside cargo) or outward (extracellular vesicles), producing predictions for partner labs to test experimentally.
The school
University of Washington: 81 labs on PI Pages, $1.7B a year on research, 694 research doctorates a year.
Reach out
A start for your email. Fill in the brackets.