how we see the invisible world guide

Wavelength

Distance between one peak and an adjustment peak

Amplitude

Height of a weight

Frequency

Number of ways within a specified period of time

Fluorescence

Absorb ultraviolet light and emits visible light

Phosphorescence

glow-in-the-dark light, absorbed and admitted after a delay.

Magnification

to enlarge the image of an object

Resolution

to distinguish two points as separate

Contrast

to distinguish objects from the background

Numerical aperture

to gather light (curvature)

What are the seven different types of light microscopes?

• Brightfield

• Dark field

• Phase contrast

• Differential interference

• Fluorescent

• Confocal laser scanning

• Two photon

Brightfield

Compound uses two lenses to magnify

Darkfield

Brightens object on a dark background

Phase contrast

Create an image by altering the wavelength of light passing through the specimen.

Differential interference contrast

Uses two beams of light with opposing directions of movement

Fluorescent

Uses fluorochromes that absorb UV light and emits visible light

Confocal laser scanning

Uses a UV laser and fluorescent dies to scan multiple layers for a two dimensional image

Two photon

Allows visualization of thick tissue samples.

Transmission election

Provides details on internal structures

Scanning electron micro scope

Produces high resolution, 3-D like images of sample services by scanning them with a beam of electrons in a vacuum.

How do scanning microscopes work?

• doesn’t use light or electrons

• Uses very sharp probes that pass over a specimen and interact with it

• Produces images with a magnification up to 100,000,000x

• Can observe individual atoms.

What are two types of scanning probe microscopes?

• Scanning tunneling microscope

• Atomic force microscope

What is the purpose of staining in microscopy?

Add color to specimens and increases contrast and resolution.

What are the two types of dyes?

• Basic dye

• Acidic dye

Basic dye

Chromophore positive, positive stain

Acidic dye

Chromophore negative, negative stain

What are the two types of staining?

Simple and differential

Simple stain

Uses single dye

Differential stain

Uses two or more dies to distinguish

Gran stain

A differential stain that distinguishes bacteria on a cell wall composition

Acid fast stain

A different stain that distinguishes two types of Gram positive cells with and without mycolic acid

Capsule

A simple stain that capsules don’t absorb.

Flagella stain

A differential stain that uses two different stains that colorized endospore green and cells pink

Place the following microscopes in order from lowest to highest magnification: fluorescent, transmission electron, Brightfield, atomic force.

1. Brightfield

2. Fluorescent

3. Transmission electron

4. Atomic force

What are the two electron microscopes?

Scanning and transmission

What are the two scanning probe microscopes?

Scanning tunneling and atomic force

What are the seven light microscopes?

1. Dark field

2. Brightfield

3. Differential interference contrast

4. Phase contrast

5. Fluorescent

6. Two photon

7. Confocal laser scanning

Which microscope has the highest magnification?

Scanning tunneling