Unit 1 – Introduction to Microscopy

I. Microscopes A. Proper Care 1.)Expensive – Carry with 2 hands 2.)Keep Glass parts clean! 3.)Never use Coarse adjustment with high Power or Oil Lens 4.)Start and stop with Low Power or Scanning Power

3 B. Terms 1.) Magnification – ability of Microscope to enlarge image of object – up to 1000X

4 2.)Resolution – ability of Microscope to show detail clearly. 3.)Field of View(FOV) Diameter – distance across light spot

5 4.)Micrometer – 1000 micrometers in 1mm 5.)Nanometer nanometers in 1 micrometer

6 C. Path of Light Bulb Diaphragm(adjusts light) Stage Hole Slide SpecimenCover Slip Objective Lens(Magnifies)Mirrors Eyepiece(Magnifies) Eyeball (Cornea to Lens to Retina to Optic Nerve to Brain)

D. Range of our Microscope =1 micrometer to 1000 micrometer. E. Parts - See sheet and picture.

F. Operation of the Microscope 1.Prepare slide 2.Put slide on stage 3.Turn light on 4.Use low power or scan power 1 st 5.Use coarse adjustment 6.Use fine adjustment 7.Adjust diaphragm

8. Switch to High Power 9. *Fine Adjust Only 10. Adjust Diaphragm 11. Add Oil Drop 12. Turn to oil power 13. Fine Adjust 14. Adjust Diaphragm

G. Total Magnification (TM) 1.TM = EP (eyepiece mag.) X OL (objective lens) 2.Scanning Power TM = 10 x 4 = 40X 3.Low Power TM = 10 x 10 = 100X 4.High Power TM = 10 x 40 = 400X 5.Oil Power TM = 10 x 100 = 1000X

II. Types of Microscopes A. Light Microscope 1. Simple microscope – one lens *Examples – Magnifying glass + Leeuwenhoeks 2. Compound microscope – two lenses: Ex. = ours

*More stuff about the compound microscope a. Real Image – Created by objective lens b. Virtual image – Image bouncing off mirror through eyepiece lens into the eyeball.

c. High Resolution occurs with shorter (blue) light waves. d. Since air refracts light, oil between slide and objective increases resolution. e..2 Micrometer is the limit that light microscopes can resolve.

B. Stereoscopic Dissecting Microscope 1. Better for large and Opaque objects 2. Magnification ranges between 4X – 40X 3. Has 2 Oculars (eyepieces) + 3d image 4. Can use reflected or transmitted light 5. real image

C. Bright Field Microscope *Most common Example = ours D. Dark Field Microscope - Bright specimen against a black field of view - poor internal details - Objective lens receives reflected light off of specimen

E. Phase Contrast Microscope – shows great Internal Detail F. Interference Microscope – shows great Internal Detail G. Fluorescent Microscope-P.62

H. Electron Microscope – Page Create the greatest magnified images with the greatest resolution 2. Very expensive $$$ 3. Cannot view live specimens 4. No colored images 5. Specimens pretreated with dyes 6. No direct observations – viewed on a screen or photographed

Transmission Electron Microscope (TEM): a)Magnifies up to 1,000,000x b)Specimen Preparation = thin slice ( nm) = staining c)Shows incredible internal detail

TEM Micrographs

8. Scanning Electron Microscope (SEM) Produces super 3d image with great external detail a)Magnifies up to 100,000x

SEM Micrographs