Page 4 - Demo

Cheek cells stained with Iodine. Mid-level magnification%u2014(left), and very high magnification%u2014(below). Can you see the swimming bacteria, circled? Motile bacteria Nucleus ? A MYSTERY When I was recording a video of an Iodine stained cheek cell, I noticed an unusual object in the water sample floating past. You can see it more clearly in the online support video. I took a snap-shot of it here, so you can have a look at it too. What do you think it is? It%u2019s a transparent sphere with what looks like several bacteria stuck on the surface of the sphere%u2014[D] below. At first I wondered if it was a single celled protozoa, but I doubted it. After a while, I think I reasoned out what this odd object is. Looking at things through a microscope requires the skills of a detective. Answer below but think about it first. Stains Different colour/chemical stains have varying effectiveness, depending on what you stain. Take a look at page 57 to determine which stains work best for the different things you wish to explore. Strange Object? Mystery solved? I believe the bubble itself is a tiny drop of saliva from inside my mouth and cheek. Such a liquid is more viscous than ordinary water, %u2018gooier%u2019, thicker, stickier, and several bacteria have become stuck in and onto it. In part 2 of this project, we%u2019ll take some more cheek cells and try to mount them on semi-permanent slides for future viewing . 19