Using microscopes Today’s objectives are: Year 7 Science – 28th of February 2013 – Cell Unit. S. Rathier To develop the some of the skills and techniques you will be needing for the rest of your scientific career!

Why do scientists use microscopes?

‘ micro ’ means so small that it’s invisible to the human eye we use microscopes to magnify things and study them microscopes have been used for 350 years!

How to use a microscope IMPORTANT STEPS: 1)Turn lens to low power (smaller lens) 2) Secure slide with stage clips and bring close to lens looking from the outside 3) Turn light on 4) Use coarse focus (move slide further away from lens until object is in focus) 5) Use fine focus if necessary 6) Try a higher magnification 7) Bring back to low power to put microscope away (and don’t forget to take back the slide!)

Magnification and resolution ‘ Magnification’ is how much an image is enlarged under a microscope. ‘ Resolution’ is the amount of detail you can see (a greatly enlarged blur is still a blur). You can calculate the magnification: multiply this number by the number this number! For example 10 ×10 = 100 or ‘×100 magnification’

Activity – 10min Use the word bank on the worksheet to label the different parts of the microscope. Think about what each part is used for ! Raise your hand when you are finished

Labelling a microscope

How do we prepare a slide? 1) Chose an objet that is thin enough to let through some light 2) Place it on a slide 3) Add a drop of water 4) Place a cover slip over it

How do we prepare a slide? 1) Place a cover slip on its edge first 2) Slowly let it fall flat

Activity – It’s a small world after all (Work on your own) 1) Take a look at the pictures taken using a microscope and take a wild guess at what they might be

A. H. G. F. E. D. C. B. Take a wild guess

A.plant seed B.velcro fabric C.mystery object X that was taken with a normal camera D.sand E.needle head F.surface of a strawberry G.human embryo H.red blood cells

How do we put microscopes away? Turn back to low magnification and low light power for the next user Wrap the cable around the light source (not the handle) Carry with 2 hands