Microscope II -- Going Cellular
Living things exist far beyond our range of sight. Looking at these things can reveal a great deal about the world around us. We need a microscope to do this. We'll be using a Leica BF-200 like the picture to the right.

Remember your basic microscope equipment and that the eye piece that you look through is rated at a specific power. In this case, the eye piece is rated at 10x or ten time normal sight (10 times bigger). The objectives are rated the same way. Light travels through the slide and into the objective, through a set of mirrors to the eye piece and into your eye which sends a signal to your brain that interpretes the light and color patterns.

Remember that if you take the value of your eyepiece and multiply it by the value of the objective you're using, you'll get an overall rating of what you are seeing (10x + 40x = 400x).

Cover Slipping
Basic operation of a slide and cover slip operation is depicted below/right. The viewing object is placed of the glass slide (often in water) and then the cover slip is placed on top of that. If your object is not in water, you'll need to get it wet before placing the cover slip on it. There are other techniques that we will use, but the cover slip technique is the most common.

Looking at Cellular Life Forms

Today we'll be looking at a bit of cellular life that comes from an organismal life form. That is, we'll be looking at cells from the inside of your cheek. The cells you'll be scraping off are the cellular part, whereas you are the organism. First, lets review a basic technique used in viewing cells under a compound microscope.

Today's Viewing Procedure:

1. Place a small drop of Iodine onto a clean slide.

2. Using a toothpick, gently scrape the inside of your cheek.

3. Place the toothpick tip into the iodine and mix. The iodine stains the cells so you can see them.

4. Place the slide under low power (4x). Draw what you see following the procedure described below.
Label the nucleus, cell membrane, and cytoplasm.

5. Repeat the procedure above for the same cells with the 10x and 40x objectives.
Remember that the 100x objectives are for oil emersion viewing (later).

6. Repeat the same procedure, but substitute an onion membrane for the cheeck cells.

The end product of this lab should be a set of 4 drawings on one page of your Lab Notebook, ready for grading.

Reporting your Results

The Procedures above shows you how to complete the procedure. Here we'll look into recording your results. In the end, you've always got to record your results.

There are four different views you'll need to record. First, you'll need to draw what you see with with your unaided eye. Then you'll record observations with the microscope looking through the first three objectives. The fourth is an objective for "oil emersion" technique,...we're not there yet.

Be careful to also record your thoughts here under the heading "Descriptions. It is as important to write about what you see as well as draw what you see. In the end you're writing and drawing so that others will know what you're thinking as well as what you're thinking. Look to the example to the right and use this as a guide to get all of your observations on one page. We don't need to belabor this one. Future observation might use multiple pages for a lab session.

When you're done you'll need to flag this notebook page for later grading.

Basic Clean Up Routine!!!

You might imagine that if we all work with microscopes and we all use them as we are supposed to and we all wait for the end of class and we all do a poor job of cleaning up the lab area and the equipment is going to get pretty grungy, pretty fast. So,...we're going to have to be more regimented regarding hygiene during wet labs.

Rule #1: Water must be controlled, cleaned up and kept off of computer equipment.

Rule #2: Equipment and slides must be left clean and in their proper storage places after use.

Rule #3: All stools, equipment and materials must be put away properly at the end of classes.

Simple, eh?