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Biochemistry Biophysics Cell Biology Neuroscience Development Evolution Genetics Genomics Structural Biology Engineering
molecules, cells and organisms

Molecules, Cells and Organisms is an innovative doctoral program that trains future leaders of scientific research in all areas of modern biology. MCO hosts faculty members from five departments on Harvard University’s Cambridge campus – Molecular and Cellular Biology, Organismic and Evolutionary Biology, Chemistry and Chemical Biology, Stem Cell and Regenerative Biology, and Physics – in addition to the School of Engineering and Applied Sciences where students work in close collaboration with both faculty and peers.

MCO News


MCO’s unique approach to the Biological Sciences Ph.D. cultivates versatility as well as depth of expertise by exposing its students to the full spectrum of modern biology. During the first year, students will complete a minimum of three 4-6-week lab rotations before selecting a thesis lab during the second semester. Lab rotations offer students the opportunity to explore divergent fields of scientific research and collaborate with faculty affiliated with five departments and the School of Engineering and Applied Sciences, providing an interdisciplinary foundation intended to inform ultimate paths of research.

In addition to lab rotations, students complete a series of rigorous foundation courses as well as electives. The MCO curriculum and one term as a Teaching Fellow hone the communication skills and critical thinking vital to a successful career in the sciences. Students take the Candidacy Examination at the beginning of the second year and conclude their preparatory studies by proposing their dissertation subjects to a committee of faculty members. Candidates devote the following years to full-time laboratory research, completing their dissertation, and earning their doctoral degree by the end of the sixth year.

Harvard University’s lively Cambridge campus accommodates a close-knit community of graduate students, postdoctoral fellows, and faculty from diverse personal and academic backgrounds. Interdepartmental volleyball tournaments, weekly lab-hosted TGIF socials, and annual student-organized retreats (past locations include the New England Aquarium and the Boston Museum of Science) contribute to a vibrant sense of community among peers at MCO.



Thinking of applying for Fall 2025? Come visit us at the HILS Preview Weekend September 26-28! More information and how to apply can be found here.

An experiment at MCO

Program Structure

The MCO graduate program consists of several broad areas of research and teaching organized along the following key areas:

  • Biochemistry, Chemical, and Structural Biology
  • Cellular, Neuro and Developmental Biology 
  • Genetics, Genomics and Evolutionary Biology 

In addition, Students can also participate in the following research communities: 

Collaboration also takes place with the broader Harvard scientific community. Students in may also pursue various certificate programs including:

Our Students

The MCO program emphasizes the breadth of biology and provides so many opportunities to learn interdisciplinary approaches in cutting-edge research projects. You can truly experience research at the Molecular, Cellular, and Organismic level here!

Juan Orozco, G3, Nett Lab

The incredible resources and welcoming environment in MCO make it one of the best places for curious students to investigate foundational questions in basic biology

Dustin Tillman, G6, Macklis Lab

The research environment of MCO is really special to me in two ways: the professors deeply care about our academic success and well being, and the students are very collaborative and supportive.

Roya Eskandari Huang, PhD ’24, Ramanathan Lab


MCO hosts faculty members from five departments on Harvard University’s Cambridge campus – Molecular and Cellular Biology, Organismic and Evolutionary Biology, Chemistry and Chemical Biology, Stem Cell and Regenerative Biology, and Physics in addition to the School of Applied Sciences and Engineering where students work in close collaboration with both faculty and peers.


(l to r, back row) Carlos Rivera-Lopez, Adriana Aguilar-Maldonado, and Claire Ang. (l to r, front row) Camila Cersosimo, Camila Bodden, Karissa Mennes, Yoland Victor, Kristal Stevens, and Natnael Belay (not shown)


The MCO Program is proud to provide an atmosphere that is supportive and inclusive of students from all backgrounds. From year to year, about 15-18% of the MCO student body identifies as members of underrepresented minority groups, which attest to the program’s dedication to a diverse student body. The MCO Program also strives to ensure that any student with a disability has equal access to the educational opportunities, facilities and resources available in the program.

MCO also works closely with the MCB Department’s Community Task Force (CTF) on Diversity, Inclusion and Belonging (DIB), as well as many of the various resources at GSAS and Harvard.

The links below provide some useful information:


MCB Community Task Force





To apply to the Program in Molecules, Cells and Organisms, prospective students should complete the Graduate School of Arts and Sciences (GSAS) Online Application. Application materials sent in any other form will not be reviewed.

When filling out the GSAS Online Application, on the “Program Selection” page please indicate “Molecular and Cellular Biology” as your Program and “Molecules, Cells and Organisms” as your Area of Study.

MCO invites applications from prospective students who have received a bachelor’s degree from an accredited college or university in the United States or its equivalent from an international institution. First year graduate studies begin at the start of the fall semester.

Although both the MCO program is comprised of faculty from several departments, MCB is the administrative host of the program. When submitting an application, prospective students will indicate the program as well as department to which they are applying.

In addition to being a training program comprised of faculty from five departments, The Program in Molecules, Cells and Organisms is a member of the Harvard Integrated Life Sciences (HILS) consortium, a federation of Harvard life sciences PhD programs, departments, and subject areas that facilitates cross-disciplinary academic and research collaboration.

For additional application details and information about the GSAS online application system, please visit the GSAS admissions website.



Harvard does not discriminate on the basis of race, color, sex, sexual orientation, gender identity, religion, age, national origin, political beliefs, veteran status, or disability unrelated to job or course of study requirements, and we actively seek applicants from historically underrepresented communities. We hope you’ll consider applying.

Why MCO?