Major Requirements

All of the courses and independent work below MUST be done on a graded basis (NO PDF).


  • MOL 214, completed with a grade of C or better. Neither AP credit nor courses taken at other institutions can be used toward the fulfillment of the MOL 214 prerequisite.
  • CHM 201/207 and CHM 202, or equivalent (one unit of chemistry AP credit plus CHM 202 or 215, or two units of chemistry AP credit. For the Class of 2027 and beyond, the equivalent is AP + CHM202/215 or requirement fulfillment through the chemistry placement test.

Note that CHM 303 and 304 or CHM 337 must be completed before the junior year (see Requirements).  

An alternate path into the department is through the Integrated Science curriculum.

General Requirements

The following courses are required:

  • Organic Chemistry  CHM 301 & 304 or CHM 337. Courses taken at other institutions can be used toward fulfillment of the chemistry requirements with approval from the Department of Chemistry.  The organic chemistry requirement must be completed before the beginning of the junior year.
  • Quantitative  Students satisfy the quantitative requirement by taking one course in statistics (SML 201, ORF 245, or MOL 290) and one course in either computer science (COS 126 or above) or math (MAT 103, 104, 175, 192, or any 200-level MAT course). SML 201 and COS 126 are the recommended choices for most students. AP credit cannot be used toward the fulfillment of the quantitative requirement. Courses taken at other institutions can be substituted for the second required course (but not for the statistics course), if approved by the corresponding department.
  • Physics  PHY 108 (strongly recommended), or PHY 103 & 104, or PHY 101 & 102. PHY 108 is a one-semester, biologically oriented alternative to the traditional full-year sequences. Pre-medical students needing two semesters of physics can combine PHY 101 or 103 with PHY 108. Neither AP credit nor courses taken at other institutions can be used toward the fulfillment of the physics requirement.

Department Core Courses

The following departmental core courses are required and, except under very special circumstances, must be taken before senior year:

  • MOL 342 Genetics (spring)
  • MOL 345 Biochemistry (fall and spring)
  • MOL 348 Cell & Developmental Biology (spring)
  • MOL 350 Laboratory in Molecular Biology (fall) or MOL 320 Experimental Molecular Biology* (spring)

*MOL 350 is offered in the fall to junior concentrators and is the conventional path for the major. MOL 320 has limited enrollment and is offered in the spring to sophomores who intend to concentrate in MOL and plan to study abroad, or have taken/are concurrently taking MOL 348 and want an early introduction to research methods and laboratory experience. MOL 320 and MOL 350 are considered equivalent courses and only one can be taken.

Junior Tutorials

Each MOL junior will be enrolled in a Junior Tutorial. In the fall, Junior Tutorials, led by postdoctoral instructors, are held once a week for 1.5 hours and are broken into two segments, each with a distinct topic area. At the end of each 4-week segment, students write a short critique of a relevant research paper assigned by the instructor. [Please note that Junior Tutorials are not considered courses and do not count toward satisfying departmental course requirements. However, they are a moderate time commitment and a requirement for the degree.] 

Other Departmentals

All students must take a total of at least eight departmentals. In addition to the four departmental core courses, students must take at least one 300, 400, or 500-level course with MOL as the primary listing. The remaining three departmentals can be chosen from among all 300-or-higher-level MOL, MOL-crosslisted, or other approved courses. Note that CHM 301, 304 and CHM 337 qualify as departmentals. Only courses taken at Princeton count as departmentals; there are no exceptions to this rule.

Integrated Science Curriculum

  • ISC 231-234 (a full-year, double-credit course) taken in the first year offers an alternative to the combination of MOL 214, CHM 201 & 202, COS 126, and PHY 103 & 104.
  • Students cannot receive credit for both an ISC course and its alternative. For full course descriptions and more information, see the Integrated Science website.