Elizabeth Stotz-Potter Headshot
Elizabeth Stotz-Potter | Laboratory Lecturer

Science Labs with a Lightboard


Within Microbial Biology (MCB 3020C), students struggle with the Quantification of Bacteria section of the lab. To count bacteria, microbiologists create serial dilutions to lower the bacterial concentration. The dilutions are plated and allowed to grow into colonies. The number of colonies is counted, and using the dilution, the original cell density (CFU/g) is then determined. Students have trouble conceptualizing the process, making dilutions, and converting dilutions and colony numbers to the original cell density. When COVID forced the Microbial Biology lab online, the material was presented to students with narrated power points, videos of lab experiments, and Zoom meetings. Unfortunately, students struggled even more with the quantification of bacteria with the online format of the lab. In an effort to enhance student understanding and promote student/instructor interaction, I (with the help of CIRT) incorporated the lightboard into my Zoom meetings. The lightboard is a piece of glass with LED lighting that illuminates what is written on the glass. Students can see me and what I have written. The lightboard gave me an easy-to-use “chalkboard” that was engaging and more adaptive than the Zoom whiteboard, narrated power points, and pre-recorded videos. I was able to interact with students, present the experimental design and the needed calculations, answer questions, and clarify concepts in a new interactive format.

Microbial Biology (MCB 3020C) is a required course for Biomedical Sciences majors and a major elective for Biology majors.  The lab portion of the course is a technique intense lab where students learn to culture, identify, and study bacteria using proper aseptic techniques.  In addition to learning how to analyze metabolic tests to identify bacterial species, students learn data analysis, how to present data in appropriate formats, and critical thinking skills.  

Historically, students struggle with the Quantification of Bacteria section of the lab.  Since bacteria are found in high concentrations (the FDA allows 1 x 106 or 1,000,000 CFU of bacteria per gram of ground meat), bacteria can’t be counted individually.  One, two, three…  Instead, microbiologists create serial dilutions to lower the bacterial concentration.  The dilutions are plated and allowed to grow into colonies.  The number of colonies is counted, and using the dilution, the original cell density (CFU/g) is then determined.  Students have trouble conceptualizing the process, making dilutions, and converting dilutions and colony numbers to the original cell density.  Normally, the concepts are introduced before the experiment using written pre-lab information about the experimental design and an extensive pre-lab talk reviewing the experimental design and chalkboard examples of the needed calculations.  Students work on a general dilution homework that is due on day 2 of the quantification of bacteria experiment.  Day 2 has a repeat of the experimental design and the calculations.  Students then have another homework more focused on the experiment.  My office hours are always busy during this time in the semester.  

When COVID forced course online, I pivoted to narrated power points to introduce laboratory concepts and to explain experiments.  I (with the help of others) made videos of myself carrying out experiments and showing the data that students then analyzed.  I held regularly scheduled Zoom meetings to answer questions and clarify concepts.  Generally, students (and I) adapted to the new format of the lab.  The loss of hands-on techniques was a disappointment for students (and me), but they were exposed to the techniques, and I added more data analysis and scientific writing assignments to make up for the loss of techniques.  

Unfortunately, students had an even harder time with the Quantification of Bacteria portion of the lab with the online format.  While narrated power points, videos, and Zoom meetings are good tools, they have drawbacks.  Narrated power points have static images which don’t lend themselves to showing the flow of an experiment.  There is no interaction between the narrator and the listener.  If students don’t understand the way I have explained something, they can’t ask a question or ask for clarification in real-time.  If students don’t understand step B in the experiment, steps C-M will make no sense either.  Videos can be better for showing the flow of the experiment but again lack student/instructor interactions.  Zoom meetings do allow student/instructor interaction, but they also have limitations.  Students attend Zoom meetings because they have questions or are confused about concepts.  I often draw a cartoon of the experiment to clarify the experimental design.  I don’t know about you, but drawing is not my strong suit, and being forced to draw with a mouse on a Zoom whiteboard usually produces more confusion than clarity.  When explaining mathematical calculations that involve exponents, Zoom whiteboard is very limited.  A simple equation (4.5 x 101/10-6 = 4.5 x 101-(-6) = 4.5 x 10-5) becomes cumbersome when typed on the Zoom whiteboard (4.5 x 10^1/10^-6 = 4.5 x 10^1-(-6) = 4.5 x 10^-5).  Without other options, students and I muddled through for three semesters.

In the summer of 2020, I participated in the Summer TOL course through CIRT.  During the course, the lightboard was introduced as a tool for videos.  In simple terms, the lightboard is a piece of glass with LED lighting that illuminates what is written on the glass.  CIRT films the presenter through the glass as they use the glass as a virtual chalkboard.  The magic of the lightboard is that once the writer and their writing are filmed, the image is inverted so that a viewer will see the writing in a readable form.  CIRT promoted the lightboard as an interactive tool for taped lectures.  I saw how it would improve my Zoom meetings. The lightboard would allow me to show the experimental design of the Quantification of Bacteria experiment.  I would be able to write, draw, and do math easily and clearly. It would be a format in which the students and I could interact.  I could easily address student questions and confusion.  

Elizabeth Stotz-Potter using Lightboard
Figure 1.  Screenshot of the lightboard being used to describe the quantification of bacteria experiment for Microbial Biology lab taken during a Zoom meeting

When I approached CIRT about using the lightboard during a Zoom meeting, they were eager to help me.  In a trial run, CIRT filmed me using the lightboard and used this camera as my Zoom visual feed.  They provided a wireless microphone for my audio feed.  To allow me to see my students on the Zoom call (or at least their black boxes), a computer was placed just beyond the camera’s field of view.  A second computer screen was placed behind the camera so I could look at the camera and “look” directly at my students.  Of course, I looked at the computer off-screen so I could actually see the students. 

After the trial run, I used the lightboard during the Zoom meeting to review the Quantification of Bacteria experiment.  I was able to explain the experimental design (how much of mixture 1 is diluted into mixture 2), clearly showing each step of the experiment and how the steps related to each other.  I was able to respond to student questions and restate and/or redraw the material so that everyone could understand.  I easily showed how to do calculations for dilutions and back calculating to the original cell density.  I was able to provide both an oral answer to student questions and a visual demonstration of the experimental design and the calculations.   All the while, I was on screen rather than becoming a disembodied voice.  The use of the lightboard within the Zoom meeting surpassed my expectations.  

Figure 2.  A short video demonstrating a small portion of the Zoom meeting. 

The student response to the lightboard was only positive.  In a survey given to students, both students who attended the Zoom meeting in person and those who watched the Zoom recording later found the lightboard engaging and helped to clarify the information.  Students who were visual learners thought the lightboard was very helpful to see how the dilutions were created. The student response during the initial Zoom meetings was so positive that I used the lightboard again in the following Zoom meetings.  

Comments from the student survey

  • It was engaging because I could clearly see what you were writing and I could also see your face, since your back wasn’t to us, as it would have been with a whiteboard.
  • I think for the purposes of a zoom meeting, it created a more true classroom experience.  Kind of comparable to writing on the chalkboard in the lab but prettier
  • The lightboard was extremely helpful as it was easy to see and understand. The use of  different color markers aided in the clarity of the calculations
  • I’m a visual learner so seeing you work out the dilutions on the lightboard helped. I found the material easier to understand when I could see it versus just listening to a lecture.  
  • I think this is a great resource for zoom meetings since the built-in zoom whiteboard is terrible to communicate any information effectively on.  This could also be cool for pre-recorded lectures (if that is possible) for concepts that you need guided examples (such as the dilutions)
  • I found the lightboard to be extremely useful because I could see what you were talking about. It felt like being in a classroom again which I liked
  • Please keep using it!

The lightboard was integrated into my Zoom meetings in the Summer of 2021.  Microbial Biology returned to face-to-face labs in the Fall of 2021, thus I have not used the lightboard again.  If I am ever forced online again, I would incorporate the lightboard in Zoom meetings again, but I would also incorporate the lightboard in the pre-recorded videos for lab introductions.  I can see a mix of both power points with images and text and lightboard segments for experimental design and calculations can be shown in a dynamic manner.

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