Exercise 1- Assessing
Start the class by asking them to respond to the following
statement in their journals or notebooks:
In your journals answer the following questions:
What are bacteria? Are they good or bad? What do they look
like? Where do you find bacteria? Where do bacteria grow?
After students have had sufficient time to respond to these
questions discuss their responses as a class. Students sometimes
don’t come up with questions easily, so discussing as
a class what they know and what they don’t know gives
more foundation for developing questions.
Exercise 2 – Learning to prepare a work area
Preparation: Before class prepare the following:
i. Spray bottles filled with a solution of 50% Lysol.
ii. 1 small bottle of “bacto-broth” made from fluorescent
Elmer’s glue (any color) diluted with water.
iii. Spread “bacto-broth” on the students’ lap
tops and water faucets
i. Explain to the class that when they handle bacteria they
need to be very careful and treat everything as a pathogen.
When they work with bacteria it is very important to disinfect
the entire work area before and after the completion of each
ii. Further explain that “As an exercise to demonstrate
the effort required to be thorough in disinfecting their work
place, including all nooks and crannies, we have developed
a way to visualize bacteria. “Bacto-broth” was
spread on the lab area prior to class. Your job is to disinfect
your lab station and eliminate all traces of the “bacto-broth.” Our
special “Bacto-broth” detector light will be used
to inspect your lab area after you have wiped it down. This
special bacto illuminator will allow us to see any remaining
traces of bacto-broth.
iii. Students should then use the spray bottle (let them know
it contains a 50% Lysol solution) and cloth from the equipment
table and begin to clean up their area.
Provide them with the following instructions:
Obtain a spray bottle and cloth from the equipment table. Wipe
down your lab station and surrounding water fixtures and handles
thoroughly. When you are finished, request an inspection with
the “bacto-light”. Any missed areas will need to
be re-cleaned! What areas did you miss? Where do you have to
pay careful attention to next time? Students should respond
to questions in their notebooks or journals and when they have
successfully cleaned up their lab area, they can be checked
off in their book.
This exercise provides an opportunity to assess students’ pre-knowledge
in their notebook responses and class discussion. Students’ ability
to disinfect an area can be assessed through their practical
application. Their understanding of why these procedures
are important will be assessed later through their lab
write-ups and responses to the embedded questions.