Teaching the Use of Micropipettes through Direct Visualization of Data: An Experiment Focusing on Technique, Skill, and Accuracy

Abstract

The correct use of micropipettes has been investigated in an undergraduate, introductory lab experiment intended for chemistry and biology majors. This lab experiment involves the use of micropipettes for accurately mixing, transferring, and applying a specific amount of dye to a cotton bandana. The data resulting from this experiment is a color wheel that displays the amount of dye transferred based on the volume of the micropipette set by the student. Student learning outcomes for this experiment include the ability to choose the correct micropipette for the volume needed, set the correct volume on a micropipette, properly draw up solutions, and use proper dispensing technique. The development of experimental foresight and improvement in students’ planning was an unintentional learning outcome. A prelab survey assessing students’ confidence in accurately using micropipettes shows that a majority of first-year students had not used micropipettes in high school (85%) but did in their first-semester science course (60%) before taking this course. The majority of those students have confidence in their ability to choose the correct micropipette, draw up the liquid, and dispense it properly. There was less confidence in setting the correct volume on the micropipette. The postlab results show that some students still had issues in setting volumes on micropipettes correctly and in dispensing the liquid. Additionally, the postsurvey suggests that setting the correct volume on the micropipette was the most learned skill from performing the lab. Overall, after performing the lab exercise, 92% of the students were confident in their ability to choose the correct micropipette and load and dispense liquid properly compared to 62% before performing the exercise.