Elisabeth Juechser ’20


Chemical and Biological Engineering

Project Title

Phytoplankton Growth Rate Measured by DNA Sequence Analysis

Presentation Link

View Elisabeth's Presentation

Certificate(s): Applications of Computing, Engineering Biology

I had the opportunity to perform research on a novel DNA-based method for determining growth rates in cultures of the marine bacteria Synechococcus. Cyanobacteria such as Synechococcus are essential contributors to oceanic production. Determining the amount of carbon fixation these bacteria are responsible for, however, requires knowing strain-specific growth rates. We used DNA sequence analysis to validate a method called iRep (index of replication) that would eliminate the need for laboratory incubations to obtain growth-rate data. Most of my summer was spent growing and sampling bacterial cultures and extracting their DNA for sequencing. I compared the DNA sequences to cell counts and size data I gathered using flow cytometry, wherein cells pass one at a time through a laser beam to determine their characteristics. I later analyzed the sequencing results from some of the DNA samples I had extracted and helped the lab process the data necessary for more in-depth analysis. This summer introduced me to research in both a wet lab and dry lab, and it solidified my intention to attend graduate school.

Internship Year


Project Category

Climate Change and Environmental Science


Ward Lab, Department of Geosciences, Princeton University-Princeton, New Jersey


Bess Ward, William J. Sinclair Professor of Geosciences and the Princeton Environmental Institute