Welcome to the Sullivan Lab
  (a.k.a. Tucson Marine Phage Lab)

** Exceptional students and post-docs: multiple positions are available. Join Us. **

As the world faces global change and resource limitation, understanding the planet’s microbes becomes necessity. This is because microbes drive the biogeochemistry that runs the planet, and are central to human endeavors, from food to health to industry. Viruses that infect microbes (phages) profoundly shape microbial populations and processes by acting as both major predators and sources of new genes.

We work to understand viral impacts on globally important microbial processes. As empiricists, we test hypotheses through direct systems-level studies of natural populations, complemented by developing and studying model phage-host systems in the lab with the goal of generating the data required for predictive ecosystem modeling. Practically, we develop new ways to "see" viruses – in the microscope, in environmental sequence datasets, in experiments – i.e., we are learning how to "count" across different data types.

Given this quantitative toolkit, current research questions include:
1) What is a viral population or species?
2) How do viral assemblages change over space and time, and what drives these patterns?
3) How do bottom-up processes impact top-down predators?


The marine cyanobacteria Prochlorococcus and Synechococcus are globally important primary producers. In spite of their small size, these cyanobacterial cells are numerically dominant over vast areas of the "desert oceans" and are significant contributors to global carbon cycling. The viruses of cyanobacteria, cyanophages, impact marine cyanobacterial diversity through mortality and gene movement through the host population. Find out more about our research...

Lab Location:
University of Arizona
Life Sciences South rm 203/207
1007 E Lowell St
Tucson, AZ 85721

Lab Phone:
(520) 626-6297