Jun 20, 2024  
USC Catalogue 2021-2022 
USC Catalogue 2021-2022 [ARCHIVED CATALOGUE]

Physical Biology (PhD)

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The interface between physics and biology is experiencing a revolution much like the one experienced by 17th century astronomers. Then, like now, new quantitative techniques allowed unprecedented observations, which in turn demanded quantitative reasoning. Galileo’s approach subjected the laws of motion to a unique blend of experiment and theory, before finally being placed in a predictive mathematical context. This style of inquiry, long favored by physicists, is now being applied to the biological sciences with increasing frequency. New experimental tools are elucidating phenomena ranging from the forces experienced by single biomolecules to the complex regulatory networks of gene expression, and the target biophysical problems range from the metabolism of individual cells to the dynamics of entire populations. The power of this physics-based approach is now widely recognized as essential for approaching all grand challenges in the biological sciences, from combating cancer to unraveling the mysteries of the brain.

Motivated by the promise of this approach at the physics/biology interface, the PhD program in Physical Biology integrates biophysical research experience leading to a dissertation with state-of-the art curriculum that (i) introduces molecular and cell biology to quantitatively minded students; (ii) presents a rigorous treatment of the physical principles underlying biological phenomena; and (iii) emphasizes the emerging physical methods that has transformed the biological sciences into a quantitative discipline. While distinct in its intellectual focus from existing graduate programs at USC, this program harnesses the critical mass of research-active biophysicists in multiple departments (physics, biological sciences, chemistry, multiple engineering departments, and the Keck School of Medicine of USC.

The Physical Biology (PBIO) PhD program is designed for graduate students who seek a quantitative framework for understanding the physical principles of biological organization and function. These students may have backgrounds from physics, engineering, mathematics and chemistry, but seek to wield their quantitative skills in the basic or applied life sciences. The program is also for students with training in the biological sciences looking for training and research opportunities grounded the physical sciences. and who seek a fundamental understanding of biological systems not emphasized in PhD programs associated with departments of biology, medicine, bioinformatics, or engineering. Graduates will likely move onto careers including medicine, pharmaceuticals and biotechnology, as well as career opportunities open to graduates with training in the physical sciences. Graduates may also pursue academic positions in the growing area of biophysics.

Admission Requirements:

Admission decisions will be made by the Department of Physics and Astronomy’s Graduate Admissions Committee, which will be advised by the PBIO Program Committee (including representatives from other departments). The prerequisite for admission to the Physical Biology (PBIO) PhD program is a bachelor’s (or master’s) degree in physics, chemistry, biological sciences, engineering or a related field that stresses quantitative training. Successful applicants will have completed undergraduate course work in mathematics (including calculus), physics, chemistry and biological sciences. All applicants for admission must take the Graduate Record Examination (GRE). Transcripts of undergraduate records as well as transcripts of any graduate-level courses are required. The TOEFL or IELTS is required of international students applying for a teaching assistantship as well as for those applying for admission only. Applicants may be admitted to the program at the beginning of the fall or spring semester.

Potential applicants are encouraged to inquire about the program by contacting one or more members of the PBIO Program Committee prior to submitting the online application. In addition to the required test scores, as appropriate, applicants will submit a detailed personal statement explaining the reasons for applying to the PBIO Program, description of previous or ongoing research, and three letters of recommendation. Applicants who are deficient in some areas may be required to remedy the deficiencies as a condition of admittance to the program.

A minimum of 60 units is required.


In addition to the elective courses listed above, relevant 500- and 400-level courses may fulfill the electives required after approval by the student’s research adviser in consultation with the PBIO Program Committee. Given the interdisciplinary nature of this program, it is likely that the relevant elective courses will evolve over time. A maximum of 4 units may be taken from approved 400-level courses. The balance of the required units are from research and dissertation (PHYS 590 , PHYS 790 , PHYS 794a  through PHYS 794z ).

Graduate students in the program may serve as Teaching Assistants, but time as a TA is not a requirement for the degree of PhD.

Finding a Faculty Adviser

Given the interdisciplinary nature of the research interests of students coming to the program, graduate students will have research group rotations as part of the first year of the program. Each student will rotate with at least two different research groups. Rotations will begin in September and each will last six weeks. Rotation 1 and 2 will occur in the fall semester and rotation 3 will occur in the spring semester. Each student should have a tentative faculty adviser before the Screening Procedure.

Screening Procedure

The screening requirements designated for continuation in Physical Biology PhD program are: before the third semester of course work the student has demonstrated satisfactory progress towards the degree, to be determined in consultation with the Program Director and an appointed faculty adviser; and an overall grade point average of B or better in at least 22 total units by the end of the fourth semester of course work (with no single grade lower than B-, as indicated above).

Only students who have passed the screening requirements are allowed to take the qualifying examination. Students who do not pass the qualifying exam may opt to continue their course work (as specified in the physics graduate program) toward a Master’s Degree in Physics.

Qualifying Examination

The qualifying examination requires the presentation (and oral defense) of a critical review of a scientific article and a research proposal prepared by the student on the area in which the student intends to do a doctoral dissertation. The qualifying exam will be taken in the fifth semester.

The written critical review and research proposal are submitted to the committee at least one week prior to a meeting with the committee where an oral examination expands on the written parts. The qualifying examination is administered by the four-member qualifying exam committee, which is composed of the research adviser, two other members of the program, and one member from outside the program. 

Language Requirement

Students in the Physical Biology PhD program are not required to pass a foreign language examination.

Dissertation and Dissertation Defense

The dissertation committee consists of three members of the qualifying exam committee including the research adviser and the outside member. An acceptable dissertation based upon completion of an original research investigation is required for the PhD in Physical Biology. The candidate must defend an approved draft of the dissertation in a public oral defense. The dissertation committee will then meet with the student in a closed session to complete the oral examination. The candidate must be prepared to answer general questions in the field as well as specific questions regarding the dissertation. Upon successful completion of the defense, the PhD in Physical Biology is awarded.

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