An experiment at MCO MCO playing volleyball MCO conducting an experiment MCO socialising
Biochemistry Biophysics Cell Biology Neuroscience Development Evolution Genetics Genomics Structural Biology Engineering
molecules, cells and organisms

The mission of the MCO program is to train future scientific leaders in basic science. Interests range across all levels of biological organization, from individual genes and molecules to organismal behavior and evolutionary dynamics. We emphasize rigorous understanding of how molecules assemble and function, how cellular processes emerge from molecular collectives, how intercellular communication in small and large networks shape physiology and behavior, and how evolutionary forces drive population-level outcomes. As data collection becomes increasingly automated and standardized, intellectual rigor and depth of conceptual thinking will become increasingly important. To teach these intangibles, we will encourage the use of models, both conceptual and mathematical, as ways to structure and focus ideas, formulate well-defined questions, and distill experimental results into meaningful insights.

MCO News

WHY MCO?

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 basic biology. During the first year, students will complete a minimum of three 8-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 across the MCO program, 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 a Preliminary Qualifying 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 departmental retreats to Cape Cod contribute to a vibrant sense of community among peers at MCO.

COURSEWORK SPECIAL ACTIVITIES

 

MCB Application Mentorship Program

The Harvard MCB Application Mentorship Program is run by MCO Graduate Students and aims to support individuals who are aspiring to pursue graduate education or a career in scientific research. We understand that the path to higher education can present unique challenges, including difficult, unclear, or hidden expectations, especially for individuals without the background, experience or resources to help overcome these challenges. We hope to provide support and mentorship to those who are applying to graduate programs and would like guidance on application writing.

Each mentee will be paired with a mentor who is a current graduate student at Harvard. Over the course of the fall semester, mentees will meet virtually with their mentors every other week, where they will have the opportunity to ask questions and get guidance on a variety of topics such as preparing strong graduate school applications, obtaining references, personal statement writing and life in graduate school. The Program is designed to support students who lack access to such resources or guidance, such as first-generation college students, students from lower income backgrounds, and students attending colleges or universities without robust resources to provide this kind of academic or career support. Race, gender, ethnicity, national origin, and other protected characteristics are not considered in reviewing applications. Please be aware that space is limited, and not all applicants are guaranteed to be matched with a mentor.

The application for 2025 is now closed. Please look out for program updates in summer of 2026.

The MCB Application Mentorship Program is not affiliated with MCO admissions, and participation in this program will not be shared with the MCO admissions committee.

Questions about the MCB Application Mentorship Program? Email mcb_amp@fas.harvard.edu

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:

  • Molecular Mechanism and Structural Biology
  • Systems, Quantitative, and Computational Biology
  • Neurobiology and Behavior
  • Development, Genetics, and Evolution

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:

Advising

Lab rotations

Teaching

DISSERTATION

INTRANET

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, G4, 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, ’25, Macklis Lab

What makes MCO stand out is the genuine freedom to explore and the encouragement to follow your scientific curiosity wherever it leads. From thoughtfully designed lab rotations to flexible coursework, the program gives you space to discover what excites you most in biology — whether that’s molecules, cells, systems, or all of the above. The culture here is deeply collaborative, and the mentorship — from both faculty and peers — has been instrumental in shaping how I think, ask questions, and grow as a scientist.

Ali Pete, G4, Hunter Lab

THE FACULTY

Graduate students belonging to the Molecules, Cells, and Organisms (MCO) training program are supported by an interdepartmental and interdisciplinary collective of faculty on Harvard’s Cambridge campus, composed of members of the MCB as its nucleus but with support from members of Chemistry and Chemical Biology (CCB), Organismic and Evolutionary Biology (OEB) and Stem Cell and Regenerative Biology (SCRB).

THE MCO FACULTY

(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)

DIVERSITY AND OUTREACH

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 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), as well as many of the various resources at Griffin GSAS and Harvard.

The links below provide some useful information:

MORE INFO

MCB Community Task Force

SUMMER INTERNSHIP PROGRAM (SROH)

Applying

APPLICATION REQUIREMENTS
DATES AND DEADLINES
FINANCIAL SUPPORT

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 only.

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.

 

 

APPLY NOW

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?