Introduction to the Discovery Labs
Course-based undergraduate research experiences (CUREs) incorporate scientific discovery, the experience of failure, opportunity for iteration, and development of troubleshooting skills (Corwin, et al., 2015). Discovery-based Laboratory I and II Molecular, Cellular, and Developmental Biology (MCDB) 1171 and 2171] are introductory-level CUREs that are one of the core requirements for MCDB majors at University of Colorado Boulder. Students take one research-based laboratory course in the first year of the MCDB curriculum; the Discovery Labs are two of the three options available to students. Interestingly, only 50% of the students enrolled in the Discovery Labs are MCDB majors. The other 50% is mainly comprised of Integrative Physiology (IPHY) and Neuroscience (NRSC) majors. Approximately 75% of the students are first-year students. The remaining students are in various stages of their education and include non-traditional students exiting military careers and post-baccalaureate students aiming to apply to medical school. As such, the course draws students from diverse backgrounds with limited experience in biology and research. However, the educational needs they report are similar: to gain skills and knowledge necessary to be competitive applicants to medical school and graduate programs and to be successful candidates for employment in the life sciences.
Discovery-based Laboratory I and II were developed to replace traditional labs that focused on briefly exposing students to many techniques in molecular biology. Education research performed over the past decade has revealed that engaging in research improves retention in science, technology, engineering, and mathematics (STEM) and increases understanding of core concepts in biology. The courses, therefore, focus on developing critical thinking skills and scientific literacy rather than laboratory skills per se. The overriding goal of the Discovery Labs is to provide students with experience in a subset of common molecular biology concepts and research techniques including approaches to screening for new therapeutics, statistical analyses, and presentation of data to the scientific community. Unlike laboratory exercises that are designed to reinforce concepts that accompany lecture topics, there is no certainty in The Discovery Labs that any research project will succeed, which reflects the inherent risks of novel research.
Both of the Discovery Labs work in conjunction with a faculty laboratory in MCDB (Drs. Corrie Detweiler and Tin Tin Su, Principle Investigators). In the fall, students in Discovery Lab I (MCDB 1171) perform a compound screen in Salmonella Typhimurium to identify novel antibiotics, and in the spring (Discovery Lab II, MCDB 2171), students focus on identifying chemotherapies in Drosophila melanogaster. In both courses, students screen through compound libraries obtained from the National Cancer Institute and using basic statistical methods, identify compounds that kill the model organisms and therefore represent novel therapeutics. After performing the screens, which are designed to provide students with technical practice and time to learn scientific background, students choose compound(s) to study in groups. They use similar experimental approaches to test their compound(s) and work closely with teaching assistants and instructors to develop and present their research at a public symposium that takes place at the end of the semester.
The objectives of the courses were developed to reflect the needs of students who are specifically interested in pursuing careers in medicine or biomedical research but also acknowledge that the many students who do not achieve these goals will need well developed critical thinking skills to understand how biomedical research affects their daily lives.
We aim for students to achieve the following course objectives (modified from course syllabi):
- Understand how the data contribute to the research being performed a sponsor laboratory and also to drug discovery in general,
- Obtain experience in molecular biology methods,
- Participate in drug screen experiments to identify compounds with potential therapeutic value,
- Statistically evaluate experimental data and interpret significance of results,
- Present data to faculty members, peers, and the public during a research poster session,
- Understand and be able to describe previous research on chosen compound(s),
- Understand and be able to describe how the data relate to previous research.
Challenges of Assessing CUREs
The success of CUREs has been measured in terms of short-term achievements like retention in STEM majors and long-term educational and career choices in STEM fields. Assessments also utilize validated instruments that measure identity as a scientist, feelings of belonging to a scientific community, and the ability to think like a scientist. These instruments are limited by the lack of specificity to the area of study and the curriculum of the individual CUREs. In the Discovery Labs, we use a multimodal approach to assessment that includes rubric-based expectations and both instructor and peer review of the quality of research defense, much like the review of scientific manuscripts and PhD dissertations and defense.
To understand whether students in The Discovery Labs achieve the course goals, the curriculum incorporates both quantitative and qualitative assessment throughout the research project that each factor into students’ final grades. For example, to determine whether students achieve proficiency in pipetting, a standard curve is produced using serial dilutions of protein. Each dilution is pipetted in triplicate and an R-squared value is calculated for the curve. Students are required to achieve an R-squared value of 0.98, or 98% accuracy, three times before advancing to the next stage of the research, which on average takes students 12 attempts. The quality of data produced in the research project is assessed statistically as students learn about normal distributions and about statistical analyses required to identify candidate compounds in their research that represent possible novel antibiotics or chemotherapies. In addition to laboratory-based assessment, development of a research project and presentation of the findings are a major focus of the second half of the semester. Students engage in peer review of research proposals, defend their proposals in a meeting with the instructor, present their research at a public symposium (The CURE Symposium) that attracts more than 800 participants and attendees, and prepares a “Specific Aims” page at the end of the semester to propose future experimentation.