An introduction to the Compound Light Microscope (This is a note check, for p. 3) You must make sure you have these correct for studying them later.

Answer to question 1 Eyepiece lens Simple microscopes use one lens to magnify. Compound microscopes use the eyepiece and objective lens (2 lenses) to magnify.

MICROSCOPE USE-SAFETY Carry the microscope with both hands, one under the base the other holding the arm and keep microscope close to your body. Answer to question 2

MICROSCOPE USE-SAFETY Fine adjustment is used for focusing on high and medium power. Answer to question 3

MICROSCOPE USE-SAFETY Coarse adjustment is used to raise and lower the stage Coarse adjustment is used to focus on low power Answer to question 4

MICROSCOPE USE-SAFETY When raising and lower the stage (all the way up or all the way down your eyes are looking from the side. You do this so the lenses don’t hit the stage. Answer to question 5

MICROSCOPE USE-SAFETY To change magnification you turn the nosepiece. You watch from the side. because you don’t want to hit the lens against the stage. Answer to question 6

Putting the microscope away Answer to question 7 a. Lower the stage b. Change to low power c. Wrap the cord d. Put the dust cover on e. Slide it onto the correct shelf with the arm facing you

Image is reversed by the lenses bending light during magnification Answer to question 8

You need thin specimens with this microscope Why? Light needs to pass through and enter lenses to magnify image. Answer to question 9

1st focus is how you set up the microscope when you first look 1. When you know the routine, it’s easy. 2. It really works! Answer to question 10

FIRST FOCUS TECHNIQUE 1. Lower the stage 2. Put on low power 3. Put on low light 4. Put object into center of aperture 5.Raise stage 6. Look and see * A SMALL AMOUNT OF FOCUSING WILL BE NEEDED BUT IT WILL THERE Aperture - the small “hole” in the middle of the stage. Answer to question 11

*Labels go outside the circle, (field of view). 1 . Your first SKETCH *Label 3 pixels, (3 different colors) on medium power. *Labels go outside the circle, (field of view). *Use a ruler for straight label lines. *Draw and color the whole field of view. Name=_________________ Location=_______________ Power = _______________

Answers questions to guide your learning Diagram Answers questions to guide your learning

Rotates =prism housing # 1 # 2

Eyepiece Also called ocular 10 X Built in pointer Turning eyepiece - moves pointer

Body tube Not strong To move it turn the prism housing Prism housing

# 10 # 14 # 13 #15

Lamp Switch If the lamp does not come on check the switch.

Base Don’t tilt microscope off base while looking. break body tube/prism housing

Coarse Adjustment knob Is used to raise and lower the stage of the microscope when first setting up or when putting the microscope away. It is used for focusing on low power. It does not get used with medium and high power

Fine Adjustment It is used on medium & high power Turning it more than once or twice means you should go back to low power & do 1st focus again Over using it will result in it not working.

Resetting FINE ADJUSTMENT Indicator marks are part 16 in the diagram When fine adjustment is not working look at the marks and turn fine adjustment until the one mark is moved to the middle of the two other marks This is how you reset fine adjustment

#12 #9

Stage Holds slide

# 11

Diaphragm It is a disc with five openings. By lining up a big or small hole more or less light enters the lenses.changes light Adjusting the amount of light is done with the diaphragm

# 4 # 8

Nosepiece You turn the nosepiece to switch lenses (objectives) It has a click that you feel when it is locked into position. You look from the side when doing this because do not want to hit the lens against the stage

Aperture The opening in the stage It has a non-magnifying “lens” and should be kept clean and dry The object you wish to look at should be centered in the aperture

# 3 # 7 # 5 # 8

Arm Faces you

Stage Clips Replaced with a mechanical stage

Correct way to put slide in Open the arm Place the slide all the way back so it is snug in the corner Close arm slowly Turn the knobs to move specimen to the center of the aperture

# 5 #6

Total Magnification The power of magnification is marked on each objective. Low power is a 4X, medium is a 10X and high is a 40X lens Because the eyepiece is a 10X lens when using low the total magnification is 10X times 4X or 40X. Low power is the best lens to search or scan with, it sees a large area. The TM of medium is 100X because the eyepiece is 10X and medium is 10X. The TM of high is 400X magnification it is the worst lens to try to find something

TM Low Power Scanning – Searching – sees large area Low Power Objective (4X) Eyepiece Lens (10X)

What it looks like

TM Medium Power

What it looks like

TM High Power

What it looks like

1st focus or Initial focus Focusing Adjust the distance the stage is from the lens 1st focus or Initial focus Watch from side raise stage coarse adj. Look in the eyepiece focus down with coarse adj.

Dry Mount

Seeing “thickness” High power Move fine up & down Layers come in & out of focus. Called “DEPTH OF FIELD”

Wet Mount Because it uses water, is called a wet mount or wm Drop of water and specimen Cover glass Because it uses water, is called a wet mount or wm

3 reasons Wet Mounts are made Increases light passing through Flattens object 3. Keeps living material moist

(slide and cover glass). Blot dry Cleaning slide & cover Rinse both (slide and cover glass). Blot dry

End of period: slide & cover glass clean up Wipe off moisture DON’T WASH!!!!!! Why? You’ll go late to next class. Takes too long

Checkout Dry slide, cover glass & return to tray Scope low power, lower stage, # shelf, wrap cord, dust cover

Adding water to wet mount slide

Your drop adding tool Finger = add “1” drop Moisten finger at the sink. “1” drop added to slide

Low cover glass slowly - avoid air pockets

Place the object on the slide

Gently lower c.g.

Absorbed extra water with p.t. Paper towel

Drawing it Water Cover glass Object or specimen

No water Dry Mount Slide Object, slide, cover glass Used for inanimate objects or things that do not need water to live.

DM hair strand of hair (trim it to fit under c.g.) cover glass over the hair

Simple Stain added to WM 1 drop of stain on edge of the cover glass paper towel on the other edge Draw water and draw the stain under the cover glass.

P.T. draws stain under cover glass Paper towel stain

Extra stain Blot the excess stain with a paper towel Why?