Science for teens

Invisible Worlds

Invisible Worlds is an exciting laboratory based microbiology short course for teens taught by a microbiologist, at Petroc College in Barnstaple.



In this lab-based course, students will learn many aspects of microbiology with an emphasis on practical work. They will learn new lab skills to carry out the laboratory activities, such as microscopy, streak plating, aseptic technique, gram staining, bacterial identification tests, plus their own investigation to test alternative antibiotics.

 Scroll down for details of the microbiology topics that will be covered in each session.

Each session is 90 minute long and will have relevant theory followed by a range of microbiology science activities and laboratory investigations to enhance learning.

An informative Course Activity Booklet and a Certificate of Participation will be given to students

Course Content

Week 1: What are cells?

  • Prepare & observe wet preps of plant / animal cells
  • Make comparisons between plant & animal cells
  • Identify live unicellular organisms
  • Sample the lab for bacteria
  • UV germs

Week 2: Prokaryotes

  • Your microbial flora & symbiosis
  • Learn how to culture bacteria (part 1)
  • The tools of a microbiologist
  • Aseptic technique

Week 3: Bacteria

  • Culturing bacteria (part 2)
  • Colony morphology
  • Staining bacteria using the Gram stain
  • Observe bacteria at 1000X magnification using oil immersion
  • Differentiate bacteria according to their shape and arrangement

Week 4: Pathogens

  • Nature’s antibiotics – the disk diffusion method (part 1)
  • Identifying bacteria in a hospital lab setting
  • Good microbes – The Microbiology Discovery Box

Week 5: 

  • Nature’s antibiotics – the disk diffusion method (part 2)
  • Zones of inhibition
  • Antibiotic resistance
  • Microbes in food

The last week is usually a tour and talk of Perrigo Pharmaceuticals in Wrafton or a tour of Pathology but this year we can’t offer this sadly.

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