Grade Levels: 6-8, 9-12

In this lesson plan which is adaptable for grades 6-12, students explore bacteria, pasteurization, and food safety in a virtual lab. Students learn how bacteria can be helpful and harmful to the human body, and then use a virtual lab to prepare samples of yogurt and test for Salmonella and E. coli bacteria.

Lesson Plan Common Core State Standards Alignments

Lesson Plan Next Generation Science Standards Alignments

Students will:

  1. Explain how bacteria can be helpful and harmful in the human body.
  2. Participate in a virtual lab, following step-by-step lab procedures to prepare samples of yogurt and test for Salmonella and E. coli bacteria.


  • Computers with internet access
  • Interactive whiteboard


This lesson plan features an interactive lab titled Gram Staining developed by our partner New Mexico State University (NMSU). Through the interactive lab, students will prepare samples of yogurt and test them for harmful bacteria. The interactive and lesson serve as an excellent introduction to a real-world chemistry investigation, or can function as a substitute for an actual investigation if the needed materials are not available.

We encourage you to preview both the BrainPOP movie and game in advance to plan how they can be adapted for your students' needs.

Lesson Procedure:

  1. Project the Graphic Organizer for the class to see. Invite students to talk with a partner about the things they already know about bacteria, and then type volunteers' responses directly into the left section of the graphic organizer..
  2. Ask students what they would like to learn about bacteria, or what questions they have. Type their responses into the middle section of the graphic organizer.
  3. Play the Bacteria movie for the class. Have students share information they learned during the movie, and type their responses into the the right section of the graphic organizer.
  4. Explain that students will have the opportunity to participate in a virtual lab centered around bacteria. Project the Gram Staining virtual lab for the class to see. Have student volunteers complete the first part of the simulation, in which the narrator explains that some yoghurt at the dairy processing plant has been contaminated with harmful bacteria. This will familiarize the class with how to advance through the various types of tasks assigned through the simulation, and teach them about the gram staining process.
  5. You may want to complete the Slide Prep and (and possibly the Gram Staining) portion of the simulation as a whole class initially to facilitate students' thinking and help them make connections to prior knowledge. More advanced students can progress directly to independent exploration of the simulation. Explain to students that they need to pay careful attention during the gram staining process, as they'll complete the process without the help of the narrator afterward.
  6. Allow students to complete the simulation on their computers with a partner.
  7. Revisit the third section of the graphic organizer, and invite students to add additional information about bacteria that they learned through the simulation.
  8. If possible, allow students to conduct a gram staining (or other chemistry investigation) in the science lab.

Extension Activities:

Explore our other science games in GameUp!