Microscope Madness Laboratory Experiment Living Environment

Name: ______Period: ______Date: ______Microscope Madness Laboratory Experiment Living Environment

Microscopes are important tools that are used in almost every aspect of biology. They are used to study living organisms and to observe phenomena we couldn’t even imagine before they were invented. Microscopes were invented in the early 1600s allowing for the microscopic world to be brought to the forefront of biology, leading to amazing discoveries in medicine, cytology, criminology, and so on. In this laboratory, you will learn how to properly use a microscope to measure and view various living and preserved specimens. Safety must be ensured to both you and the animals you are working with. BE CAREFUL not to kill any of our creeping creatures and be careful with all liquids, glass slides, and the microscopes so nothing gets broken. Remember, if you break anything that is glass or spill a chemical, please ask the teacher to clean it up for you, DO NOT clean it up yourself. By the end of this laboratory, you should be able to label the various parts of the microscope and understand their function. You will also learn how to properly carry, use and store a microscope. Also you will learn how to prepare a wet mount slide, stain a specimen, calculate magnification as well as determining the size of your field of view.

Materials:  Compound light microscope  Slides and cover-slips  Specimens  Toothpick  Iodine stain  Kim wipes

When you are done, please return any creeping creatures or slides to the correct disposal jars or storage bins, wash off your stained slides, return the microscope to low power and turn off the power before wrapping the cord around the arm for storage. Part 1 – Microscope Parts and Functions

Identify the following parts on the microscope. Observed how the base, lens, and diaphragm can be moved (what is the result?). Answer the following questions after your observations.

Objective Lenses Diaphragm Fine Adjustment Ocular Lens Stage Course Adjustment Arm Stage Clips Light Base Nosepiece

1. Always carry a microscope with one hand on the ______and the other have on the ______.

2. A microscope should be stored with the ______objective in place.

3. Always bring a specimen into focus using the ______objective first.

4. Use only the ______adjustment when focusing with the high power-objective.

6. How is the magnification of a compound microscope determined?

Part II – Using the Microscope

Obtain a “letter” from the teacher. Observe your sample under the low power objective with your microscope.

Does it look the same direction as it does on the stage?

If not, draw the way it appears through the microscope below.

When you are done, please return any creeping creatures or slides to the correct disposal jars or storage bins, wash off your stained slides, return the microscope to low power and turn off the power before wrapping the cord around the arm for storage. What happens when you move the “letter” to the left on the stage? Does it move to the left in the microscope’s field of view? YES or NO

Which way did it move? Left or Right

Part III – Preparing a Wet Mount Slide

Obtain a slide from your teacher. Place a small drop of water on the slide. Using a toothpick, gently scratch the inside of your cheek. Mix the contents on your toothpick with the water on the slide. Place a coverslip over the cells by placing it perpendicular to the slide and gently lowering it, preventing bubbles from forming on the slide.

Observe your slide under the microscope using low power. Once it is in focus, switch to high power.

Can you see anything? What would make it clearer? Yes! A stain would make the specimen darker, allowing you to observe the cells characteristics.

To stain your cells on the slide, place a drop of iodine on the slide. Drain off the excess by placing the corner of a paper towel next to the drop so it absorbs the excess.

Draw what you see under high-power:

When you are done, please return any creeping creatures or slides to the correct disposal jars or storage bins, wash off your stained slides, return the microscope to low power and turn off the power before wrapping the cord around the arm for storage. Part IV – What is That?

Obtain a depression slide. Place a drop of water and one of the creeping creatures from front the lab bench on your slide. DO NOT USE A COVERSLIP! Observe your creature under low power at first, focus the image, and then switch to high power.

Record what you observe it doing, what you notice about it and draw a picture of it for each creeping critter you observe in the space below.

Creature Name: ______(use the diagram guide to identify the creature)

Observations: Picture:

Part V – Slide Discoveries

Use your compound microscope to observe three prepared slides of your choice from the provided selection. If can also create your own slide from something you have observed in the room, just get the specimen approved by Ms. Holding BEFORE you create your own slide. You will be required to determine the total magnification of the image as well as calculate the field of view. Using this information you can determine the approximate size of a single specimen.

Slide Name: ______

Total Magnification:

Field of view:

Estimated Size of Specimen:

When you are done, please return any creeping creatures or slides to the correct disposal jars or storage bins, wash off your stained slides, return the microscope to low power and turn off the power before wrapping the cord around the arm for storage. Slide Name: ______

Field of view:

Slide Name: ______

Field of view:

Analysis Questions: (answer in complete sentences on a separate sheet of paper)

1. What kind of problems will air bubbles on a slide cause?

2. Why do you always focus with the fine adjustment under high power?

3. If you were tracking a bacteria and the organism moved from the bottom of your field of view to the top of your field of view, what directions would you move the slide to continue watching the bacteria?

4. Determine the size of the spores shown in the microscope photograph to the right. Use the metric ruler lines to solve for spore size. Units shown are in micrometers. When you are done, please return any creeping creatures or slides to the correct disposal jars or storage bins, wash off your stained slides, return the microscope to low power and turn off the power before wrapping the cord around the arm for storage.