MICROSCOPY

LAST CLASS• We discussed Taxonomy, and the Linnaeus system of

classifying organisms• Who can remember the subgroups in Linnaeus

Taxonomy?• Hint: King Phillip Came Over For Grape Soda• Kingdom – Phylum – Class – Order – Family – Genus –

Species • Looked at Dichotomous Keys

TODAY•We will start our microbiology unit by looking at the proper use of a microscope•We will discuss magnification and size calculations•We will learn how to properly perform a scientific drawing•We will apply our knowledge by looking at organisms under the microscope, and create scientific drawings of them.

MICROSCOPY• Though no one is entirely sure on who is credited with the invention of the microscope, it is a critically important invention.• It has helped expand science and Biology into an entire unseen world, and has allowed us to gain insight into the broader diversity of life, the organisms that cause disease and helped us better understand ourselves and where we have come from.

MICROSCOPY• Today we will be looking at Optical (or Light) Microscopes.•Uses Light to detect small objects• Two types• Simple• Compound*

•As we discussed last day, there are also microscopes known as Electron Microscopes

SIMPLE MICROSCOPE

COMPOUND MICROSCOPE

Plant Cells

Human Blood Cells

staphylococcus aureus

Hang on… what’s wrong with the naming of this organism up there ^?

Correct writing:Staphylococcus aureus

ELECTRON MICROSCOPES• Use beams of electrons to create an image of a specimen. Capable of much higher magnification and resolution compared to light microscopes

GUESS THAT IMAGE

Pirahna Plant from Super Mario

Suction Cups of an Octopus

Rare species of poisonous mushroom

The underside of a human finger

GUESS THAT IMAGEThe bottom of a gecko’s foot

Sharks Skin

The surface of the human tongue

Some clever fourth option

GUESS THAT IMAGE• SKITTLES!!!

• EASTER MORNING

• HUMAN EGG CELLS

• SPORES OF A MUSHROOM

GUESS THAT IMAGE• TEETH OF A MUSSEL

• SHARKS MOUTH

• ALIEN (FROM AVP)

• HUMAN FINGER

BACK TO OUR LIGHT MICROSCOPE REALITY…

• I will briefly go over the different components of the microscope…

•On the sticky notes in front of you, write down the name and definition of each part we discuss.

•When we have FINISHED discussing the parts, attempt to match the sticky note to the part on the microscope.

PARTS OF THE MICROSCOPE1. EYEPIECE: The eye piece contains the ocular lens

I. The Ocular lens is named so as it is the lens closest to the eye. In a compound microscope it provides 10X magnification

2. Objective Lenses: Magnification ranges from 10X, 40X and 100X

3. NOSE PIECE: Holds the objective lenses

PARTS OF THE MICROSCOPE CONT’D

4. Stage Clips: Hold Slide in place

5. Stage: Supports the slide

6. Base: Supports the microscope

7. Diaphragm: Regulates amount of light on the specimen

MICROSCOPE PARTS8. Light Source: Projects light upwards through specimen and diaphragm

9. Coarse Adjustment Knob: Moves stage up and down for focusing

10. Fine Adjustment Knob: Used to sharpen the image

11. ARM: Used for support when carrying microscope

TO DO NOWTry to place sticky notes on corresponding part of the microscope

When you have finished raise your hands- If correct, then I will give you microscope worksheet

- If anything is out of place, adjust until correct

MAGNIFICATION CALCULATIONSIn order to truly understand what you are seeing under a microscope, it is very important to take the magnification of the specimen into account.

First, and simply, we must calculate the total magnification:

Remember the Ocular lens provides 10X magnification

The objective lenses provide 4X, 10X, 40X or 100X magnifications

POWER OF MAGNIFICATION CALCULATION

Total Mag. = Ocular X Objective

Total Mag. = 10 X Objective

Total Mag. = 10 X (4, 10 , 40 or 100)

ACTUAL SIZE CALCULATION• Just by examining your specimen in a field of view you can estimate roughly the size of that organism.

• You start by looking at the “Number of fits” that specimen would take to fit the diameter of the field of view (ALWAYS Lined up horizontally)

ACTUAL SIZE CALCULATION• We have calculated that there are

4 “fits” for this organism in our field of view

• Next we look at the Field of View Size• The field of view is the diameter

of the area we are observing under the microscope

2000 μm

ACTUAL SIZE CALCULATION• To calculate the actual size of the specimen of interest

use the equation:

• Actual Size = The diameter of the field of view (in μm) / # of fits

• Previous page example

• Actual size = 2000μm / 4 fits = 500μm

FIELD DIAMATERSWe will use the following Field Diameters when doing our calculations:Objective Lens Magnification

PowerField Diameter (mm)

Field Diameter (μm)

Low (4x) 40x 4.5 4500

Medium (10x) 100x 1.8 1800

High (40x) 400x 0.45 450

OIL IMMERSION (100x)

1000x 0.18 180

TO DO NOW• Fill in Microscope Diagram

•Work on Unit Conversions in Microscopy package