Biotechnology apprenticeship for secondary-level students: teaching advanced cell culture techniques for research

Abstract

The purpose of this article is to discuss small-group apprenticeships (SGAs) as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments using both flow cytometry and laser scanning cytometry during the 1-month summer apprenticeship. In addition to effectively and efficiently teaching cell biology laboratory techniques, this course design provided an opportunity for research training, career exploration, and mentoring. Students participated in active research projects, working with a skilled interdisciplinary team of researchers in a large research institution with access to state-of-the-art instrumentation. The instructors, composed of graduate students, laboratory managers, and principal investigators, worked well together to present a real and worthwhile research experience. The students enjoyed learning cell culture techniques while contributing to active research projects. The institution's researchers were equally enthusiastic to instruct and serve as mentors. In this article, we clarify and illuminate the value of small-group laboratory apprenticeships to the institution and the students by presenting the results and experiences of seven middle and high school participants and their instructors.

Figure 1

Representative flow cytograms from two students' samples containing THP-1 cells labeled with both propidum iodide (PI) and FITC–annexin V intended to illustrate healthy versus nonhealthy cells. (A) This flow cytogram shows 11,068 gated events from cells labeled with PI and FITC–annexin V after incubation for 42 h in an uncoated polystyrene tissue culture well, a healthy, negative control. (B) This flow cytogram shows 11,529 gated events from cells labeled with PI and FITC–annexin V after incubation for 42 h in a tissue culture well coated with silicone. The observed low viability is not reflected in the average percentage viability (Figure 2A), which suggests improper cell handling during labeling or uncured material during incubation. The quadrant markings were established experimentally according to the limits of single-labeled samples of healthy THP-1 cells labeled with either PI or FITC–annexin V (data not shown). Cells in the lower-left quadrant of the plots have low PI and annexin V staining and are considered “viable.” Cells in the lower-right quadrant have low PI intake and high annexin V staining and are considered to be “early-apoptotic.” During the analysis, intact cells of interest are isolated (or gated) by virtue of their 0° and 90° light-scattering characteristics.

Figure 2

THP-1 cells were cultured for 24 h (black) and 42 h (gray) in the presence of various cured test materials. Cells were stained with PI and FITC–annexin V and analyzed by flow cytometry. (A) Cells that did not stain with PI, labeled “viable.” (B) Cells that did not stain with PI but did stain with FITC– annexin V, labeled “early-apoptotic.” Cells incubated in uncoated polystyrene tissue culture wells served as the negative control. Early-apoptotic, positive control cells were incubated in uncoated wells and 12 μM camptothecin was added 6 h prior to labeling. Unfortunately, the positive control samples had low percentages of early-apoptotic cells, and their cytograms indicated that a majority of the cells had already progressed to late-stage apoptosis, thus the control protocol could be optimized.

Figure 3

Graph and table of one student's flow experiment for THP-1 cells incubated with adhesives for 42 h. Viability, as measured here, includes both lower quadrants of the cytograms, where cells have only minimal PI intake and therefore overall larger percentages of “viable” cells than those shown in Figure 2A.

Figure 4

LSC analysis of adherent mouse aortic endothelial (MAE) cells after culturing on a micropatterned substrate. (A) Micropatterned silicon substrate embossed with a 10-μm square-grid pattern created in photoresist on a standard 4-in. silicon wafer. (B) MAE cells stained with PI (nuclear stain) after incubation and fixation on the micropatterned substrate. Cells are shown growing in the wells of the micropatterned substrate.

Figure 5

Results of mentors' Likert-scale assessment of SGA experience and background.

Figure 6

Results of apprentice/participants' Likert-scale assessment of SGA experience and background.