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People: Team Members



Joshua Modell

Principal Investigator

Josh got his PhD from MIT in the lab of Michael Laub and did his postdoctoral work at Rockefeller University with Luciano Marraffini. Outside of the lab, Josh enjoys cooking, eating, ball sports, and constantly filling his rear bike wheel with air. Josh wonders whether there is a hole or if that’s simply what it’s like to be a bike commuter, riding and pumping, riding and pumping. Josh claims to be training for a half-marathon, but some question his dedication, most of all, his wife Cleo. Cleo mentioned that there is a 5k on the same day as the half-marathon, and Josh felt patronized, which is exactly what Cleo wanted. Now, everyone’s watching to see what he will do… | @jwmodell


Philipp Andesner

Research Specialist

Philipp received his MSc in Biotechnology from the University of Life Sciences in Vienna, Austria. In his free time, he enjoys reading, walks on the waterfront and contemplating which movie to pick next from his ever-growing watchlist. But these are tough decisions, so Philipp quite often ends up binging some culinary TV show instead, while trying to improve his sourdough bread. Flour trails between couch and kitchen tell the tale. Until he bakes the perfect loaf, the quest for the crispiest crust and the fluffiest crumb continues...


Marissa Feeley

BCMB PhD Candidate

Marissa obtained her B.S. in Biology from Suffolk University in Boston, MA. She worked at the Broad Institute conducting CRISPR screens in human cancer cell lines before returning home to Baltimore, MD to dip her pipette into microbiology. Outside of lab, Marissa enjoys rock climbing, biking, visiting local breweries, going to the beach, and confidently singing the wrong lyrics to songs. She also collects musical instruments that she intends to teach herself, only to find she’s instead mastered the art of collecting dust on said instruments. Maybe if she didn’t binge true crime shows and podcasts, she’d actually have the time to learn.


Joshua Garcia Colon

BCMB PhD Candidate

Josh earned his B.S. in Cellular and Molecular Biology from UAGM in San Juan, Puerto Rico. He then did his post-baccalaureate work at UNC Chapel Hill where he studied the contact-dependent growth inhibition system of Burkholderia thailandensis. He came to graduate school with an interest in bacterial defense mechanisms and is now at the front row watching bacteria/phage battles on his day to day. In his free time, Josh enjoys being active, doing sports, relaxing at a scenic spot, or driving someplace new.

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Nick Keith

BCMB PhD Candidate

Nick received his BS in Biology from the University of North Carolina - Chapel Hill. Outside of lab, he devotes the majority of his time to planning his next backpacking adventure (both the hiking and world-traveling types). Since he’ll never actually be able to find the money or time for those trips, he instead spends his free time playing the banjo and other instruments, making home renovations, and trying to clicker train his stubborn cat. If all goes as planned, he recommends following his newly-trained adventure cat’s Instagram influencer account so he can help his girlfriend pay her medical school tuition.

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Rhett A. Snyder

BCMB MD/PhD Candidate

Rhett received his BS in Microbiology at Indiana University where he discovered his love for bacteria starting with Caulobacter crescentus. After studying the human immune system for a while, he decided to go back to his prokaryotic roots and research the (arguably cooler) bacterial immune system. When not in lab, Rhett is most often found caring for his vastly growing indoor jungle. Philodendron are his favorite of the Araceae, but he is always open to having his mind changed. Some current species in cultivation include P. paraiso verde, P. billietiae variegata, and P. joepii, not that he’s super proud of them or anything. Outside of bacteria and plants, Rhett enjoys a variety of board games, time spent near any water source, and quiet evenings with his partner, Levi, and two cats, Jinx and Nixi. 


Peter Sparklin

Research Technologist

Peter received his M.S. in Bioinformatics from University of Maryland Global Campus. Outside of his budding interest in molecular biology and coding, Peter loves growing flowers, hiking, and writing bad poems about dogs and cats to put in Rachael's lunchbox. He can proficiently operate a backhoe, snowplow, and/or chainsaw if the situation calls for it


Marie Stoltzfus

BCMB PhD Candidate

Marie received her BS in molecular biology from Millersville University. When she isn’t pipetting or watching bacteria battle phage under the microscope, she enjoys running and biking around Baltimore, cooking (mostly) vegetarian food, enthusing over science with elementary school students, and playing the cello. She has backpacked alone through foreign countries and jumped out of a plane at 15,000 feet, but catching a waiter’s attention still makes her nervous every time.


Alex Tsantilas

Research Technologist

Alex materialized (verb) in a collaboration between the Modell Lab and the Johns Hopkins Krieger School of Arts & Sciences. Created from building blocks of keys (noun) and good-looking (adj) toasters (noun), he explores this Earth with one objective – to bungee-jump (verb) with Kevin Bacon (person), no matter the cost. As an infant, Alex loved Switzerland (noun), and that passion follows him today, with his extensive flamethrower (noun) and zombified (adj) lemur (noun) collections. Outside of the lab, Alex never turns down an intergalactic (adj) protest (noun), though his fear of the Mariana Trench (noun) prevents him from living the sinister (adj) life he desires. If you see him, approach slowly, as you would a pterodactyl (animal) or mantis shrimp (animal).


Sarah Voss

BCMB PhD Candidate

Sarah received her BS in Biochemistry at Texas State University before packing everything she owns into her Prius and driving across the country to join the BCMB program and the Modell lab. When she’s not in lab, she is probably in her Prius. Going anywhere that’s not home and doing anything that doesn’t cost too much money. Sarah really has to save her money because she spends it all on iced lattes. Yes, it would cost less if she just made coffee at home or used the fancy espresso machine in lab, but we all know it tastes better when someone else makes it. And Sarah is definitely drinking lattes for the taste- not because she’s addicted to caffeine or anything.


Rachael Workman

BCMB PhD Candidate

Rachael received her BS and MS in Biology from WV and Portland State Universities. When not in lab grappling with the mysteries of microbial genetics, she can be found hugging her three dogs, cat and husband, playing gaelic sports, gardening, playing euphonium, or laying on the couch drinking whiskey and thinking she does too many things. She is the lab's resident expert on Bachelor Nation and always prefers to be wearing hiking boots because you just never know.

Former members

Bella Cabrera - BSI-SIP Summer Intern, Summer 2020; PREP Scholar, 2021-2022              

Sakshi Chavan - Biotechnology Master's Student, 2019-2021

Leo Graeff - Undergraduate Researcher, 2018-2020

Binh Nguyen - Research Technologist, 2018-2020

Teja Pammi - Research Technologist, 2018-2020

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