Dr. Sarah McLean
Playing around with Simulations from Biointeractive
This week in ETEC 533 we learned about the T-GEM model; a way for instructors to introduce scientific inquiry during instruction. The "T" stands for technology (we looked at the role that simulation can play in this process), whereas G= generate, E= evaluate, and M= modify. Essentially, you are getting students to observe and suggest relationships between variables, evaluate those relationships (by providing simulations or other hands-on activities), and then modify the relationships based on new data. One way that I thought this could work in my own practice would be in teaching students about ELISAs and why a standard curve is so important. Read on to see my ideas about how to implement the T-GEM framework.
The topic I chose to demonstrate a T-GEM teaching cycle is the concept of serial dilutions in ELISA reactions. An ELISA is a molecular technique that is used to identify the presence of an immune response (by evaluating the presence of a particular antibody), or identify the presence of a protein (for example, to assess the levels of a hormone). Blood and urine samples are common patient sources of data. These tests are very common and you can even find one at the dollar store- a pregnancy test! However, I have found that students struggle with understanding the role of the dilution factor when creating their standard curve to create the "readable range" of an ELISA. An ELISA is a highly sensitive technique so it can detect molecules in the picomolar range. Students have difficulties creating a standard curve to read the ELISA, and it is essential to have a valid and accurate standard curve in order to determine the quantity of an unknown. Interestingly, the Howard Hughes Medical Institute (HHMI) has a website that has a number of virtual experiments (you can check it out at biointeractive.org.
They have an ELISA simulation, but interestingly, they do NOT create a serial dilution in a way that would work with small concentrations! Thus, I would have the student work through the simulation, and compare and contrast how this would work with the actual picomolar range of solutions that we work with- you can see the actual simulation here: https://media.hhmi.org/biointeractive/vlabs/immunology/index.html (Links to an external site.).
I think that the use of this simulation would be interesting because it would also get them to think beyond the basic premise of "what one reads or sees on the internet is correct". You can see my TGEM cycle in the diagram below.