Microscope Lab Do Now: Pick up lab and preread the whole lab, answer pre-lab questions when finished reading. Not before, after!

Set up your Cornell Notes As Follows (skip lines……): I. Safety II. Magnification III. Preparing Wet Mount IV. Focusing V. Electron Microscopes Define: resolving power, depth of view

Compound Light Microscope I. Safety Always carry with 2 hands Arm and base Place away from edge of table Always start with stage all the way down Light off Lowest power Always return the microscope to this position when finished

Eyepiece Course Focus Fine Focus Scanning Obj Arm Power Body Tube Nose piece High Power Low Power Clips Stage Diaphragm Light Base 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

II. Magnification Eyepiece Rotating nosepiece has 3 objectives What you look through May have pointer inside 10x Rotating nosepiece has 3 objectives Scanning (short and red) 4x Low (medium and yellow) 10x High (long and blue) 40 x

Total Magnification = Eyepiece X objective Scanning 4x = 40x total Low 10x = 100x total High 40x = 400x total Eyepiece 10x

Controlling light First plug in and turn on the light. Under the stage is a rotating disc that turns and clicks It may have numbers on it Turning the diaphragm (disc) controls the amount of light

Slide #1- hair Slide #2 - letter “e” Prepared slide of crossed threads

III. Preparing Wet Mount 1. Place letter e in the middle of your slide. 2. place 3 drops of water on top of your letter e 3. put cover slip in the edge of the puddle of water and release 4. do not press or move the cover slip

Place slide on stage and secure IV. Focusing Place slide on stage and secure Use scanning objective and try to center the crossed threads then focus Use course focus (large knob) first Fine focus (small knob) second Which way does the slide move if you push it left? Push right? What affect does changing the diaphragm have on the image? Change to low power Notice any change? Draw

Change to high power USE ONLY FINE FOCUS! Course focus can press into slide and crack the glass, squish specimen, and damage the objective. It may take time to focus correctly - practice How does the view of the image change? Draw don’t SQUISH THE SLIDE!!!!!! 

The Wonderful Letter e Preparing a wet-mount Cut out a lower case letter e Place on slide Carefully add water drop Try to keep the e looking like this… e Carefully place cover slip on letter

Place slide on microscope and secure Start with scanning objective - center and focus. See any thing unusual? Change to low power and draw Change to high power and draw

Depth of View Notice that as you increase magnification you see more detail of less of the image. You also see layer of the image that you can focus through More of less

Resolving Power A measure of the clarity of an image.

Closure Complete post lab questions Turn in lab

V. Electron Microscopes Scanning or SEM Uses electrons bounced off the surface of the specimen Transmission or TEM Electrons through the specimen Live specimens cannot be used

Electron Microscope (2 kinds) *

a)Transmission Electron Microscope TEM- Electrons go Through the Specimen (non living SpecimensOnly)

b)Scanning Electron Microscope SEM –Uses electrons Bounced off the Surface of the Specimen (non living Specimens only)