Skip to main content


The Microbiology major encompasses a wide range of topics from human health to biotechnology, synthetic biology to microbiomes, and biofuels to bioremediation. This major provides students with a solid background in biochemistry, genetics, molecular biology and basic microbiology, and then allows them to tailor their studies for an emphasis in general, medical, biotechnological, or environmental microbiology. The Microbiology major provides a foundation for careers in a variety of fields including healthcare, epidemiology, clinical diagnostics, food microbiology, microbial fermentation, environmental testing, health and environmental public policy, biotechnology, bioenergy, and biomanufacturing. The Microbiology major will also provide an excellent foundation for graduate studies in microbiology, virology, infectious diseases, biotechnology, and related fields, as well as for medical, dental, nursing, veterinary and pharmacy school.

The major requirements below ONLY apply to students who were admitted to UC San Diego in Fall 2018. 

Lower-Division Requirements

  • Biology: BILD 1, 3, and 4
  • Chemistry: CHEM 6A, 6B, 6C and 7L
  • Organic Chemistry: CHEM 40A, 40B, and 43A
  • Mathematics: MATH 10A, 10B, and 11 or 20A, 20B, and 11
  • Physics: PHYS 1A/1AL, 1B/1BL, and 1C/1CL or 2A, 2B, 2C and one lab (2BL, 2CL, 2DL)

Upper-Division Requirements

Note: Any given course can only satisfy one major requirement

  • Genetics (BICD 100)
  • Molecular Biology (BIMM 100)
  • Microbiology (BIMM 120)
  • Laboratory in Microbiology (BIMM 121)
  • Microbial Genetics (BIMM 122)
  • Biochemistry - complete one of the following courses:
    • Structural Biochemistry (BIBC 100)
    • Metabolic Biochemistry (BIBC 102)
    • Biochemical Structure and Function (CHEM 114A)
    • Biochemical Energetics and Metabolism (CHEM 114B)
  • Microbiology Core Courses - complete three courses from the following:
    • Immunology (BICD 140)
    • Genome Diversity and Dynamics (BIEB 146)
    • Evolution (BIEB 150)
    • Evolution of Infectious Diseases (BIEB 152)
    • Virology (BIMM 114)
    • Medical Microbiology (BIMM 124)
    • Genome Science (BIMM 172)
    • Biology Meets Computing (CSE 180)
  • Biology Electives - complete at least ten or twelve units of upper-division coursework offered by the UC San Diego School of Biological Sciences (a total of 48 upper division units is required for completion of the major).
    • Upper-division Biology elective units may be completed with courses numbered 100-189 taken through UC San Diego’s School of Biological Sciences.  Elective units may include one quarter of BISP 195, up to four BIxx 194s, and one quarter of either BISP 193 or BISP 196/197/199. Electives may also include SIO 121, 123, 124, 125, 126, 127, 128, 129, 131, 132, 133, 134, 138, 147, 181, and 189.  Students are required to meet the School of Biological Sciences residency requirement .
    • Only one BISP 196/197/199 can apply towards the major.  Subsequent quarters of BISP 196, 197 or 199 may be applied toward college and university requirements.

Additional Requirements

Minimum Grade Requirement

  • All courses required and used toward any biology major requirements must be taken for a letter grade and completed with a C- or better.
  • The minimum grade requirement applies to all lower-division, upper-division, required courses taken in other departments, as well as courses transferred and used toward major requirements.
  • Exceptions will be made for those required courses that have a P/NP only grading option (e.g., BISP 199).
  • The minimum major GPA requirement is 2.0.

Please note: The degree audit may not automatically reject D grades for the major. If your degree audit appears to apply a course in which you have earned a D to a requirement for the major, please contact a biology advisor.

Upper-Division Unit Requirement

To receive a Bachelor of Science from UC San Diego, all students must complete 48 or more units of upper-division course work within the major.

Biology Residency Requirement

To receive a Bachelor of Science in Biological Sciences from UC San Diego, all students must complete at least twenty units of upper-division coursework in the School of Biological Sciences with a grade of C- or better. This coursework must directly apply to the student’s Biology major requirements, and must be taken while officially enrolled at UC San Diego. Courses completed outside of the UC San Diego School of Biological Sciences will not be counted toward the residency requirement.