HOW TO USE THE MICROSCOPE

Unlock a whole new view of the world under the microscope!

The Compound Light Microscope Has two magnifying lenses * Ocular (eye lens) * Objective lenses (high, medium, low) Uses light for viewing Most commonly used microscope

REVIEW of the Basic Parts of the Microscope

What does each part do?

Magnification The ocular lens (eyepiece) has magnification written on it. Each microscope has 3 or 4 objective lens with magnification written on it. Ocular lens x Objective lens = Total Power Power Magnification Low ___ x ___ = ___ magnification Med. ___ x ___ = ___ High ___ x ___ = ___

Let’s check your memory…

Carrying a microscope Use both hands One hand under the base One hand holding the arm Carry the microscope close to your body.

Resolving Power = ability to see details clearly Resolving power is reduced as you go to higher powers of magnification Fabric 40 x 100 x

Field of View Lighted circle when looking through the ocular On higher magnification not everything in field will be in sharp focus this is how you know the specimen has depth, layers

Orientation of Specimens Letter e on a slide put under the microscope. As seen under the microscope What does this tell you about what the lens system does to a specimen?

The Art of Focusing Step 1- Obtain a slide and place it on the stage over center of opening. Step 2- Rotate the nosepiece so that low objective is in line with the body tube.

Step 3- Raise the body tube using coarse adjustment knob until lens is 2 cm above stage. Step 4- To begin to focus on low power, use the coarse adjustment knob. When specimen comes into view, then use the fine adjustment to bring specimen into sharp focus.

Step 5- Adjust the diaphragm (amount of light) to get the most detailed view. Step 6- Increase to a higher magnification by rotating the nosepiece until objective clicks into place. Step 7- Use only the fine adjustment knob to focus images on medium and high power.

When finished viewing a slide.. If viewing another slide, start on low power and repeat the focusing process. If finished for the day, remove slide from stage and return to origin. Clean any slides made by you. Rotate eyepiece to lowest objective . Turn off light.

Making a Wet Mount Slide Step 1- Obtain a clean slide and coverslip. Step 2- Place specimen in the middle of the slide. .

Step 3- Place a drop of water on the specimen. Step 4- Slowly lower the cover slip at a 45 degree angle until it touches slide. Gently tap out any air bubbles if present.

Step 5- Remove excess water at edge of coverslip with a paper towel Step 5- Remove excess water at edge of coverslip with a paper towel. (If specimen dries out while viewing add a drop of water at edge of cover slip.)

Making a Stained Slide Follow the same procedures as for making a Wet Mount Slide, except use the stain specified in directions.

Stains allow you to see more detail and structures, depending on the stain used.

Teacher Check- Slide Preparation Your slide under the microscope will be checked using the following criteria: ____ Started with clean materials ____ Complete water (or stain) coverage, edge to edge ____ No visible air bubbles. ____Specimen is centered under slide. ____ Specimen is focused and in view (under magnification directed in lab directions.)

Guidelines for Biological Drawings Drawing Materials: use a pencil NOT a pen (so as to allow for erasing and shading), used colored pencils if image is seen in color Positioning: Field of view= circle, position drawing as you see in your circular field of view

Size- Draw to scale (what you see in the field of view is drawn similar size on your paper field of view- circle) Accuracy: Carefully observe what you “see” under the microscope Draw what you see! Pay attention to details like- texture, size, color, shapes

Labeling Slide Diagram Labeling : Label all specimen parts that are known to you and/or stated in the directions to be labeled EX: label cell wall, membrane, nucleus Title: title of slide, or what is being viewed Magnification: state the power that is being viewed and diagrammed Type: prepared slide, stained slide, or wet mount

Diagram Teacher Check You will be assessed on your diagram skills using the following criteria. DO NOT remove your slide from the stage, since it is needed to compare to your diagram. ___ Accuracy – Diagram looks similar to what was observed ___Detailed-- Details such as color, texture, shape, etc. are included in diagram ___ Size-Diagram is of appropriate size to see details, drawn to scale ___ Labeling-All parts of the diagram are labeled as instructured in lab directions. ___ Slide Labeled-Title, Magnification, Type, is included

REVIEW- Homework Assignment Use your textbook, Appendix D Use of the Microscope and Slide Preparation Procedures (starting on page 1070) to assist you. Microscope Structures, Functions and Magnification (page 1 in new packet) Steps of Using a Microscope, Steps to Making a Wet Mount Slide (page 2 in new packet)