Invisible Worlds is a practical microbiology course for students aged 12 upwards run by a microbiologist and microbiology teacher at Petroc, Old Sticklepath Hill in Barnstaple, North Devon.

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 and bacterial identification tests. 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 in the form of a short presentation 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.

£65 per student




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
  • Practise aseptic technique using Bunsen burners
  • Carry out streak plating
  • Germs game!

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
  • Nature’s antibiotics – the disk diffusion method (part 1)

Week 4: Pathogens

  • Nature’s antibiotics – the disk diffusion method (part 2)
  • Identifying bacteria in a hospital lab setting
  • Sneeze Zone
  • Good microbes – The Microbiology Discovery Box

Week 5: Perrigo Pharmaceuticals in Wrafton, tour & talk
or if the above can not go ahead for any reason then we’re back in the Petroc lab for:

  • Microbes in food
  • Food spoilage investigation


To see what we offer for primary school aged children click here.

If you’re home-educating, you may be interested in these clubs.