Electrophoresis

The ability to understand and interpret data is a critical aspect of scientific thinking. However, although data analysis is often a focus in biology majors classes, many textbooks for allied health majors classes are primarily content-driven and do not include substantial amounts of experimental data in the form of graphs and figures. In a lower-division allied health majors microbiology class, students were exposed to data from primary journal articles as take-home assignments and their data analysis skills were assessed in a pre-/posttest format. Students were given 3 assignments that included data analysis questions. Assignments ranged from case studies that included a figure from a journal article to reading a short journal article and answering questions about multiple figures or tables. Data were represented as line or bar graphs, gel photographs, and flow charts. The pre- and posttest was designed incorporating the same types of figures to assess whether the assignments resulted in any improvement in data analysis skills. The mean class score showed a small but significant improvement from the pretest to the posttest across three semesters of testing. Scores on individual questions testing accurate conclusions and predictions improved the most. This supports the conclusion that a relatively small number of out-of-class assignments through the semester resulted in a significant improvement in data analysis abilities in this population of students.

Recent recommendations for biology education highlight the role of authentic research experiences early in undergraduate education as a means of increasing the number and quality of biology majors. These experiences will inform students on the nature of science, increase their confidence in doing science, as well as foster critical thinking skills, an area that has been lacking despite it being one of the desired outcomes at undergraduate institutions and with future employers. With these things in mind, we have developed an introductory biology laboratory course where students design and execute an authentic microbiology research project. Students in this course are assimilated into the community of researchers by engaging in scholarly activities such as participating in inquiry, reading scientific literature, and communicating findings in written and oral formats. After three iterations of a semester-long laboratory course, we found that students who took the course showed a significant increase in their understanding of the nature of authentic research and their level of critical thinking skills.

Restriction analysis is especially important in checking the structures of recombinant DNA molecules and in analyzing an unknown DNA. This chapter shows some examples with some typical restriction analysis problems encountered by scientists in the laboratory. Observing the sizes of fragments produced, scientists determine restriction site locations that would give them the patterns they see. A linear (not circular) piece of DNA is digested with the restriction endonuclease EcoRI and gives fragments of the following sizes: 3,000, 3,600, and 3,400 bp. When digested with BamHI, the DNA molecule gives fragments of the following sizes: 4,500, 3,000, and 2,500 bp. A double digest with EcoRI and BamHI gives fragments of the following sizes: 2,500, 500, 3,600, 3,000, and 400 bp. The distances between the restriction sites in base pairs are indicated, and the sites EcoRI or BamHI are appropriately labeled.