Our Microscope 6 th Grade Science Certain materials are included under the fair use exemption of the U.S. Copyright Law and have been prepared according to the multimedia fair use guidelines and are restricted from further use. Photo by D. Tresten, 2002 Compound microscope

Eye piece Body tube Base Coarse adjustment knob Arm Fine adjustment knob Revolving nosepiece Diaphragm Light source Stage opening Stage clips Stage Magnify 10 X Objective lens

IMPORTANT! Watch How Light Travels Through a Microscope Note: Just study the vertical (up and down) portion of the light beam! The horizontal (right/left) portion is not in our microscope. Molecular Expressions Microscopy Primer: Anatomy of the Microscope - Transmitted Light Microscopy Optical Pathways: Interactive Java Tutorial

Which type of lens is in a microscope? Convex Lens (Pooches out in the middle!) Concave Lens (Caves in in the middle!) A convex lens is used in the microscope.

In Which Objects would Convex Lenses be Used? Click to see 7 images

In Which Objects might Concave Lenses be Used? Click to see 7 images

Total Magnification - What is it? To find the total magnification at which a microscope is set, just multiply the power of the eyepiece (10x) times the power of the objective that is in place. Click to practice finding total magnification…

Magnification: Multiply If… Eye piece 10 X Objective Lens 4 x Total magnification is 40 X

Practice calculating Total Magnification: If the eye piece is 10 x and the objective lens is 40 x the magnification is... If the eye piece is 10 x and the objective lens is 20 x the magnification is... If the eye piece is 10 x and the objective lens is 10 x the magnification is x 200x 100x

Microscopes are not toys!! They are expensive tools!!

Microscope Rules 1. Always use two hands to carry a microscope! One hand goes under the base and one on the arm.

2. Do not touch the lenses. If they are dirty, only clean with special lens paper.

3.Be cautious when handling glass slides. Notify teacher if a slide breaks. (Students should not handle broken glass.)

4. Always keep the scope away from the _______ of the_________. Care of the Microscope Page 3 of 3 edge table

How to Use the Microscope

1. STAGE down! (away from objectives) 2. Plug in the microscope. 3. Twist 4x (Low-Power) OBJECTIVE until it clicks into place! (using nosepiece NOT objectives) 4. Stage CLIPS out! 5. SLIDE on 6. Stage CLIPS back in (carefully placed on top of slide) 7. Switch on LAMP Before using the Scope, Wake It Up: Use of the Microscope Page 1

1.Make sure that the stage is all the way DOWN and slide is in place. Down In place

2. Set Scope to Low Power (4x) In other words, set the 4x objective in place over the stage opening. 4x Objective

3. Turn the coarse adjustment knob to raise the stage to focus the slide.

4. Next, turn the fine adjustment knob until the specimen is in sharp, clear focus.

Use of the Microscope Page 3 5. If there is too little light, rotate the disc diaphragm to another opening. How to Focus on a Specimen, Cont’d:

Close-up of disc diaphragm (as seen from underneath the stage) Do you see the largest hole that lets the most light pass? Which hole transmits the least light?

What is this? “Field of Vision” in a Microscope Pointer in eyepiece

Always put our microscopes “to bed” after labs: Use of the Microscope Page 4 1.Lamp off 2.Unplug 3.Stage down (Away from objectives) 4.All slides are removed 5.Clips IN 6.Clean stage 7.Dust cover ON 8.Put all slides and other materials in proper places

Wet Mount with a Squashed Air Bubble in It

How to Add More Water to a Wet Mount without Starting All Over Again!

Why Learn to Use a Microscope? To see cool things like anything on the following web page! /moviegallery/pondscum.html /moviegallery/pondscum.html

Magnify 10x Support / Hold lenses in place Support microscope Focus quickly but imperfectly (coarsely) Hold body tube/Carry Focus very slowly more perfectly (actually moves the stage away from/toward the objectives) To turn objectives (lenses) into place over specimen To magnify 40x Allow more/less light Send light up through specimen Allow light to reach specimen / Catch spilled matter To magnify about 10X Hold slide To magnify about 4X