Lesson Objectives Describe the equipment needed for microscopy and

explain how each piece is used.

Calculate the linear magnification of drawings and the actual size of specimens in images of known

magnification.

Image from wikimedia commons: http://commons.wikimedia.org/wiki/File:Microscope-blank.svg

MagnificationThe image we see through the light microscope has been magnified.

Objective lens x eyepiece lens

Modern Microscopy

Image: d2540-6 by USDA on Flickr (CC): http://flic.kr/p/dPqvvY

Modern Microscopy

Image: d2540-6 by USDA on Flickr (CC): http://flic.kr/p/dPqvvY

As we develop more and more sophisticated and precise imaging tools, we can see more detail of the cells and molecules that make us.

Scanning electron microscopes deliver high-resolution, 3D surface images of structures, whereas transmission electron microscopes give us a view inside cells and organelles.

Emiliana huxleyi

Image from: http://earthguide.ucsd.edu/earthguide/imagelibrary/emilianiahuxleyi.html

Transmission electron micrograph of HIV particles.

HIV-1. Transmission electron micrograph, via wikimedia commons: http://commons.wikimedia.org/wiki/File%3AHIV-1_Transmission_electron_micrograph_AIDS02bbb_lores.jpg

120nm

False-coloured scanning electron micrograph of HIV (green) budding on a lymphicoyte (blue) http://en.wikipedia.org/wiki/File:HIV-budding-Color.jpg OR http://phil.cdc.gov/phil/details.asp?pid=10000

1μm

Scanning electron micrograph of HIV particles budding on a human lymphocyte.

Some units that I use & knowUnit abbr. Metric equivalent

kilometer km 1,000m 1 x 103m

meter m 1m 1m

centimeter cm 0.01m 1 x 10-2m

millimeter mm 0.001m 1 x 10-3m

micrometer μm 0.000 001m 1 x 10-6m

nanometer nm 0.000 000 001m 1 x 10-9m

÷1,000

÷1,000

÷1,000

X 1,000

μm = micrometersWe usually use this in discussion of cells.

There are 1,000μm in one mm.

write this correctly

Here is an image from a microscope. How do you know how big it really is? Any ideas what it is?

Magnification x150

Lets practice a couple of questions (worksheet 1)

Now lets play with the microscopes!

The next few slides show some worked examples to help you with future calculations

Extension / PlenaryTry questions 1 – 3 (all parts) in the text book pages 6-7

Labeling the parts of the microscope activity:http://www.biology.ualberta.ca/facilities/multimedia/uploads/intro-biology/microscope.html