Antibiotic Lab Investigation (Day 2 of 3)

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Students will learn the basic details regarding the background history of antibiotics, the nature of bacterial organisms, and explore the phenomenon of antibacterial/antimicrobial resistance in a hands-on manner.

Big Idea

Bacterial infections, the use of antibiotics, and their increasing resistance to many antibiotics is a growing and widespread issue for medical science. Students will investigate this issue in a hands-on lab.

Learner Goals

Note: I recommend that you first check out this resource in order to get the most out of this lesson!

In high school I took several drafting classes and, for a while, I had hoped to become an architect. With respect to planning instruction and teaching, I feel that I can still live out the detailed approach to building something intricate and complex even though the product is a lesson rather than a certain "built environment".

The lesson-planning template that I uploaded to this section is a comprehensive overview of how I approach lesson planning. This template includes the "Big Three" aspects of the NGSS standards: Disciplinary Core Ideas, Crosscutting Concepts, and Science Practices. Of course, there are many other worthy learning goals, skills, instructional strategies, and assessments that can be integrated into a class session. I don't feel compelled to check every box but, rather, use it as a guide to consider various options and tailor the lesson in light of these.

With regard to this particular lesson, I want students to develop some basic knowledge about cell diversity; that is some cells are prokaryotic and others eukaryotic. Furthermore, given the high-stakes issue of antibiotic resistance in medical science, students ought to be informed about the problem and ways to reduce its effects. Finally, students will be formally introduced to the particular inquiry procedures that I want students to follow in this, and every, lab investigation. The scaffolding of knowledge and skills here will serve them well in the sessions of this class.

I hope you get some value from my work! Please find the more intricate details of this lesson plan there.

NOTE: This investigation usually takes 3 class periods (165 minutes for me) to complete.

Anticipatory Set ("Hook")

5 minutes

Since this is an extension of Day 1, it would be advisable to make a brief reminder of the goals for the lab (including the a review of each team's inquiry question and the respective hypothesis and the key points covered the previous class period). I also prefer to have students share the key details of their protocol (such as the manipulated variable, responding variable, and controlled variables). In some areas these might be referred to as independent, dependent variables. Finally, personal protection protocols are reinforced, such as washing hands before and after handing any apparatus, wearing gloves, and goggles, not leaving lids of Petri dishes open for too long, etc.).

Instructional Input/Student Activities

45 minutes

(Day 2 of 3)

Students ought to implement their experimental design plan.  This should include:

  • properly labeling the Petri Dishes including the name of each respective antibiotic disk (in each quadrant), the group number and period number (e.g. P3G5 which, in my case would mean Period 3 and group 5 of a total of 8 groups), and the date. 
  • carefully innoculating the agar with the stock bacterial sample
  • applying the three different antibiotic disks
  • taping up the two halves of the Petri dish
  • and storing them in the incubator (set at 37 C) for overnight growth (approximately 23 hours) and interaction between the antibiotics and bacteria.

View the following pictures of a student inoculating a Petri Dish with E. coli before adding the antibiotic disks and placing it into the incubator.

Closure: What did we learn? Where do we go from here?

5 minutes

1. Wrap-up for day: Make sure that all student teams have properly set up their Petri Dishes and that they have been stored in the incubator in order to allow for as much growth as possible.

2. Ensure that all lab work areas have been sterilized (by washing with clorox solution or substitute) and that all students have disposed of gloves in trash and thoroughly washed their hands (i.e. sterile technique).

Click here for Day 3 of 3...