"Micro" (Greek!) refers to tiny, "scope" refers to view or look. Microscopes are tools used to enlarge images of small objects so they can be studied. The compound light microscope is an instrument containing two lenses, which magnifies, and a variety of knobs to resolve (focus) the picture. Because it uses more than one lens, it is sometimes called the compound microscope - in addition to being referred to as a light microscope. In this lab, we will learn: How to correctly use the compound light microscope. Prepare and use a wet mount. Determine the total magnification of the microscope. Explain the proper procedure for focusing under low and high power using the microscope. Read the directions for each section on the cards provided at each station. Write all answers on this worksheet! Do not make any marks on the materials at each station! Station 1 Solve the Mystery 1. 9. 17. 2. 10. 18. 3. 11. 19. 4. 12. 20. 5. 13. 21. 6. 14. 22. 7. 15. 23. 8. 16. 24. Station 2 Make it Simple 1. Complete the chart to show your observations using the water drop and hand lenses. LENS Single water drop Two water drops Three water drops Hand lens OBSERVATIONS Distance from page (mm)
2. What do you predict would happen to the magnification if you used more drops of water? 3. How does the view of the e with the hand lens compare to the water lens? Determining Total Magnification There are numbers stamped on the eyepiece and on each objective lens. Locate these numbers. You will use these to calculate the total magnification when using each lens. You calculate by using the steps below. The magnification written on the ocular lens (eyepiece) is The magnification written on: a. the scanning objective x b. the low power objective is x c. the high power objective is x The total magnification is determined by multiplying the objective lens power with the ocular lens power. Calculate the powers of magnification for each objective lens. Eyepiece Objective Band color lens power Power Total Power of Magnification Station 3A Virtual Microscope Lab Go to the following website: https://www.brainpop.com/games/virtuallabsusingthemicroscope/ Website: www.brainpop.com Select Science Scientific Inquiry Microscopes Gameup Under the Games banner select Virtual Labs Using the Microscope Work your way through the lab and make sure you understand the proper use of the microscope pay particular attention to the steps, process and methods for focusing as you go to higher and higher power. This is critical so you do not damage the microscope s ocular lens. An even fancier virtual microscope can be found at: http://www.biologycorner.com/worksheets/microscope-virtual.html Try it out. Pay close attention to the steps used to focus on higher power.
Station 3B Using the Microscope 1. Read the Station 3 card to answer these questions: a. What should you do before viewing a slide? b. Which objective provides the highest magnification -short, medium, or long? c. What is the warning? 2. Choose a prepared slide and look at it in the microscope. Draw a view of it at three different powers of magnification low, medium and high. Calculate the magnification. Name of Specimen: 3. Select two additional specimen slides and make 2 sketches of each: on low and high power. Name of specimen:
Specimen Name: 4. How does the view of the specimen change as the power of the magnification increases? Write at least two sentences that summarize your observations. Station 3C Spice It Up Procedure: Prepare a dry mount of a sample of salt, sugar and pepper: For each sample, transfer a small amount onto the slide with tweezers. Place a cover slip over the specimen and observe. Remember to always start focusing with the low power (4X)! Under low power, examine the salt crystals. Examine the sugar, noting any differences from the salt crystals. Examine the black pepper, again noting any differences from the salt. Draw a detailed picture of what you see on you observation sheets. Repeat for one of the spices. 1. Why were you instructed to make a dry mount of these rather than a wet mount? 2. Many kitchen spices such as pepper and cinnamon originate from plants and are produced by a grinding process. Why do you think these would look different under a microscope than the salt and sugar?
Station 5 Scope Basics Ratings: = Great =OK = Poor Activity Rating Best Time (Optional) #1 -Vocab Challenge # 2 -Parts & Pieces Station 6 Review and practice 1. When you are finished, go to: http://sciencespot.net/ Click the Kid Zone graphic in the upper right-hand corner. Click Microscopes to find the links you need. Visit the sites listed below. Site #1 MOS Scanning electron Microscope. Work through the site filling in the attached worksheet Site #2 Virtual Electron Microscope Work through the site filling in the attached worksheet. Site #3 (optional) - PBS Microscope Activity Try several challenges. How many did you do? HINT: Click the More link to see all the challenges. Site #4 (optional) - Microscope Parts and Function Quiz See how quickly you can score 100%