Parts of a Microscope Microscope Basics

Label the Compound Light Microscope (Handout) Ocular lens Body Tube Coarse Adjustment Knob Fine adjustment Knob Revolving nosepiece Objective lenses (4x, 10x, 40x) Arm Stage Stage Clips Diaphram Light source Base

Taking a look at the world…. Look around the room…. What types of things can you see in plain view (with your eyes)? Now, use the hand-held magnifying glass…. What new things can you see? What types of things might you see if these things were magnified, 10x, 40x, 100x, x or even x?

Field of view and Magnification Microscope History and Development

Microscope History Anton Van Leeuwenhoek The father of microscopy first to see and describe bacteria.

Robert Hooke Robert Hooke: sees cork through a microscope lens and noticed some "pores" or "cells" in it. First person to use the word "cell”

Technological Advances in Microscopes

Compound Light Microscope Uses light Has two lenses Magnification is limited to 2000x We use this type at LHHS (our magnification is 400x)

Transmission Electron Microscope (TEM) Uses beams of electrons Magnification of x Has two limitations: Good only for thin specimens Only dead cells can be observed

Scanning Electron Microscope (SEM) Electrons are reflected from the surface of the specimen Produces a 3-d image Good for the thicker specimens Lacks the magnification and resolution of the transmission electron microscope

SEM

Guess the Picture: These are images using a SEM microscope! Cat flea

SEM Mosquito head

SEM Porcupine Quill

SEM Toilet Paper

SEM Mascara Brush

SEM Mosquito Head Close-up

SEM Foot of a house fly

SEM Dentist Drill

SEM Velcro

Magnification Magnification = Objective lens X Ocular lens (4x, 10x, 40x)(10x)

Calculating the size of a specimen binder

Calculating the size of a specimen Example under med. objective Object size = Size of field of view Number of objects across field of view Object size =1.72 mm 14 Object size =0.1 mm