The Microscope Microscopes Zacharias Janssen Janssen Robert Hooke
The Microscope
Microscopes Ø Zacharias Janssen, Janssen Robert Hooke and Anton von Leeuwenhoek all contributed to the design of the compound light microscope Ø With the invention of the microscope came many ground breaking discoveries about how life looked on a cellular level ØThings that were “invisible” are now visible!
How a Microscope Works Microscopes use convex lenses are made of curved glass (and glasses etc. ) Convex Lenses bend light and focus it in one spot.
How a Microscope Works Ocular Lens (Magnifies Image) Body Tube (Image Focuses) Objective Lens (Gathers Light, Magnifies And Focuses Image Inside Body Tube)
The Parts of a Microscope
Ocular Lens Body Tube Revolving Nose Piece Arm Objective Lenses Stage Clips Diaphragm Light Source Coarse Adjustment knob Fine Adjustment knob Base Skip to Magnification Section
Body Tube • The body tube holds the objective lenses and the ocular lens at the proper distance Diagram
Nose Piece • The revolving nose piece holds the objective lenses and can be turned to increase the magnification Diagram
Objective Lenses • The Objective Lenses increase magnification (low is 4 x, Medium is 10 x and High is 40 x) Diagram
Stage Clips • These 2 stage clips hold the slide/specimen in place on the stage. Diagram
Diaphragm • The Diaphragm controls the amount of light on the slide/specimen Turn to let more light in or to make dimmer. Diagram
Light Source • Projects light upwards through the diaphragm, the specimen and the lenses Diagram
Ocular Lens/Eyepiece • Magnifies the specimen image • Has a magnification of 10 x Diagram
Arm • Used to support the microscope when carried. Holds the body tube, nose piece and objective lenses Diagram
Stage • Supports the slide/specimen Diagram
Coarse Adjustment Knob • Large knob that moves the stage up and down (visibly) for focusing your image Diagram
Fine Adjustment Knob • smaller knob moves the stage SLIGHTLY to sharpen the image Diagram
Base • Supports the microscope Diagram
Magnification
Magnification • To determine your total magnification …you just multiply the ocular lens by the objective lens • Ocular 10 x Objective 40 = So the object is 400 times “larger” Objective Lens have their magnification written on them. Ocular lenses usually magnifies by 10 x
Caring for a Microscope • Clean only with a soft cloth/tissue or lens paper • Make sure it’s on a flat surface • Don’t hit it against anything or anyone • Carry it with 2 HANDS…one on the arm and the other under the base
Using a Microscope • First KNOW WHAT YOU SHOULD BE LOOKING AT or FOR!!! • Start on the lowest magnification (Low Objective) • Place slide on stage and lock clips • Adjust the COARSE knob first! • Adjust light source if necessary • Use fine adjustment to focus or sharpen the image
Using a Microscope • DO NOT use the coarse adjustment knob on high magnification…you’ll break the slide!!! • Only use the FINE ADJUSTMENT knob on High power • When in doubt, and you can’t seem to focus on Medium or High, ALWAYS go back to LOW power
References • • • http: //www. cerebromente. org. br/n 17/history/neurons 1_i. htm Google Images http: //science. howstuffworks. com/light-microscope 1. htm
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