On the Microbe Trail: An Introduction to Bacteria and Aseptic Technique

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In this series of exercises, learners predict the conditions necessary for bacterial growth, test their predictions and at the same time practice the aseptic techniques and safety procedures needed when working with bacteria. In the first exercise, learners' prior knowledge of bacteria is determined including the conditions they believe necessary for bacterial growth. Armed with petri dish and cotton swabs, learners obtain samples from the places at their site with these conditions. Learners discover how to prepare their lab areas for microbiology work, pour and swab plates, and seal, label and store plates.

Quick Guide

Preparation Time:
10 to 30 minutes

Learning Time:
1 to 2 hours

Estimated Materials Cost:
$10 - $20 per group of students

Age Range:
Ages 14 - 18

Resource Types:
Activity, Experiment/Lab Activity, Lesson/Lesson Plan


Materials List (per group of students)

  • disinfectant in spray bottles (50% Lysol solution)
  • old rags
  • "bacto-broth" (fluorescent Elmer's glue diluted with water)
  • "bacto-light" (hand held black light)
  • prepared NaOH agar plates
  • phenolthalein solution
  • inoculating loops
  • flame source if using metal inoculating loops
  • nutrient agar
  • sterile petri dishes
  • cotton swabs
  • permanent markers
  • journals


  • Life Sciences
    • Cells
    • Diversity of Life
      • Viruses and Bacteria
  • Physical Sciences
    • Chemistry
  • Mathematics
    • Data Analysis and Probability
      • Data Analysis
      • Data Collection
  • The Nature of Science
    • The Scientific Process
      • Conducting Investigations
      • Gathering Data
      • Formulating Explanations
      • Communicating Results


To use this activity, learners need to:

  • see
  • see color
  • read
  • be mobile
  • touch

Learning styles supported:

  • Involves hands-on or lab activities


This resource is part of:

Access Rights:

  • Free access


  • Ziegenhirt, Laura ; Cuccinello, Jenny