Major Requirements



  • MOL 214, completed with a grade of C or better
  • CHM 201/207 and CHM 202, or one unit of chemistry AP credit plus CHM 202 or 215, or two units of chemistry AP credit

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

General Requirements

The following courses are required:

  • Organic Chemistry CHM 301/303 & 302/304/304B, 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 or ORF 245) 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
  • MOL 345 Biochemistry
  • MOL 348 Cell & Developmental Biology 
  • MOL 350 Laboratory in Molecular Biology

All four departmental core courses count toward the eight required departmentals. No substitutions are allowed except in the case of study abroad which, if it entails intensive research and with advanced permission, can substitute for MOL 350. Note that MOL 345 may be taken concurrently with CHM 304/304B.

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 301/303, 302/304/304B, and CHM 337 qualify as departmentals. Only courses taken at Princeton count as departmentals; there are no exceptions to this rule.

Any course that is a prerequisite, requirement, or departmental must be taken for a letter grade (no P/D/F).

Integrated Science Curriculum

  • ISC 231-234 (a full-year, double-credit course) taken in the freshman year offers an alternative to the combination of MOL 214/215, CHM 201 & 202, COS 126, and PHY 103 & 104.
  • CHM 337 offers an alternative to CHM 301/303 and CHM 302/304/304B.
  • Students cannot receive credit for both an ISC course and its alternative. For full course descriptions and more information, see the Integrated Science website.

Study Abroad (fall semester junior year)

Juniors who wish to study abroad must complete at least one departmental core course (MOL 342, 345, 348, or 350) beforehand.

While abroad, students must complete the equivalent of the fall semester junior paper. This requirement may be fulfilled by completing an independent scientific literature reading program, including weekly communication with a Molecular Biology faculty member and written reports, while abroad. Alternatively, students may join a journal club in a research laboratory abroad, with close monitoring by a Molecular Biology faculty member.

Study abroad that entails intensive laboratory research can, with advance permission, substitute for MOL 350. None of the other departmental core courses may be completed abroad.