Surface Microbiology Science Fair Projects and Molds

Working With Molds

Molds are found all around us. Environmentalists study the growth of molds in homes for health safety purposes. You will do a safe experiment when you study molds in food.

Objectives

This lesson has been developed for 6th grade students, but is easily adaptable to other levels.
Students will:

-assemble a wet-mount slide
-demonstrate the use of a microscope, focussed on the specimen
-demonstrate the mastery of observation
-utilize vocabulary of mold structural parts in journal and/or
presentation/questioning by Teacher

Test bacteria on any surface with the Surface Microbes Experimenter Kit.

See the wide variety of discounted student microscopes.Excellent for HomeSchooling too!

Materials Needed

Paper towel or paper napkin
Clean, blank slide(s)
Slide cover(s)
Water
Mold from piece of bread
Forceps
Microscope

Strategy

In preparation for this lesson, students/teacher will already have prepared some bread mold. I usually wipe the classroom floor (if uncarpeted), a chalk ledge, or window sill with half a slice of home-made bread. I lightly spray it with water, and then EITHER place in a sealed baggie, OR lay on a saucer in an out-of-the-way place. If you use the saucer method, you may need to re-moisten the bread every day or two.

Once the mold has started to grow (2-3 days), you may want to allow it to dry out, so that student(s) or you who are sensitive to molds will be less so. I ALWAYS CAUTION against touching or breathing the molds.

Part A (I usually give the directions for making a wet-mount 3 times; tell, show, tell. My directions differ from our science text.) Place a clean slide on top of a paper towel or piece of paper. Place 1 or 2 drops of water on it. (Use the tip of your finger, or use a dropper.) With the forceps, take a TINY pinch from the bread mold and MASH around into the water. (Tiny because we are using a microscope, and just a bit will look big; the mold structures are sturdy, and will not be harmed. Having them spread out will allow the light of the microscope to shine through it so the structures can be easily seen.) Holding the slide cover by the sides between forefinger and thumb, slide 1 edge TO THE EDGE of the water droplet, and then DROP the cover on to the slide. (If there are any air bubbles, they will show up as silver shapes, but should not be a problem.)

Part B Secure the slide on the platform with the slide clips. (Holds the slide steady for viewing.) Make sure that some of the mold is over the light which is coming in via the mirror or lamp. Then with the lowest-powered lens (usually the shortest) in place, focus by slowly turning with the coarse adjuster until you see something; then adjust the fine knob until the "picture" is clear. DRAW what you see in the journal, or on the observation sheet. LABEL the ball-like top "sporangium", and the stem AND root-looking parts "hyphae". COMPARE it with your team members.

Performance Assessment

A. Can prepare a wet-mount slide, using material from the experiment
slide cover atop slide specimen 1

slide cover indicates air bubbles-some 1
-few 2

B. Can put a slide on the microscope platform

light shining on specimen in lens 1

specimen focussed-somewhat 1
-sharply 2

C. Can label/name -microscope parts (max. based on YOUR microscope)
1 pt. per part 0-6
-mold parts 1-2
-did drawing 1
-labeled drawing 1
-1 pt. per part labeled 1-3

PASS = 11 pts. or more; FAIL = 10 pts. or less.

What other microbiology explorations can you create?