CUREing biochemistry lab monotony

Abstract

Undergraduate research experience is critical to success in post-graduate research settings. The recent movement away from "cookbook" style labs to course-based undergraduate research experiences (CUREs) in undergraduate laboratories has allowed universities to provide inclusive research experience while bypassing the limitations of extracurricular apprenticeships. This paper describes an upper-level biochemistry CURE designed to provide students with an introductory experience to graduate-level research by studying a suspected DNA helicase. This CURE is designed to span multiple semesters, where each student cohort builds upon the work of previous semesters. Pre- and post-course surveys were employed to assess student confidence in bench skills, perceptions of the course, and project ownership. The results show that the incorporation of lab meeting-style recitations and poster presentations led to higher project ownership, while overcoming troubleshooting was a significant challenge. Furthermore, confidence in every experimental technique increased significantly in all but one instance. Based on these results, this CURE is providing students with a realistic experience in graduate-level research.

Figure 1.. Student confidence in core skills.

Students ranked their confidence with six skills pre- and post-semester: agarose gel electrophoresis, sodium-dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), bacterial plasmid transformation, restriction enzyme digestion of DNA, protein purification, and enzyme activity assays. Under each skill, three plots. Left: mean scores by semester for pre- (open circle) and post-semester (closed circle) surveys. Semesters are abbreviated as F/S (Fall/Spring) and the last two digits of the year. Error bars denote standard deviation. Increases in confidence denoted with an asterisk (*) were determined to be statistically significant using a paired Student’s t-test (p < 0.05). Center: histogram of pre- to post-semester changes for all students. Bars are colored according to movement direction (red = loss, yellow = no change, blue = gain) and increasing hue intensity corresponds to larger changes. Right: pie chart showing the percentage of students who reported a loss (red), gain (blue), or no change (yellow) in confidence.

Figure 2.. Post-semester student survey results.

A) Mean survey scores by semester for each of the four categories. Scales were normalized to the maximum possible score for each category (Collaboration, 4; Discovery, 6; Iteration, 6; Ownership, 5). A linear regression was performed in Python and is displayed as a solid line surrounded by the shaded 95% confidence interval. B) Open-ended reflection responses for most rewarding (left) and challenging (right) aspects of the course. Responses were inductively analyzed to identify recurrent themes and binarized, where each theme received a score if it was mentioned (1) or not (0). Each student response could contain multiple themes.

Figure 3.. Correlations between survey items.

A Pearson correlation of the change in normalized mean semester scores for each question was performed in Python. The dendrogram (top) shows the hierarchical sorting. Increasing hue intensity represents stronger positive (blue) and negative (red) correlations. Color-coded boxes and question abbreviations bordering the correlations correspond to Table 1. Questions are paraphrased for readability.