Care and Use of the Microscope

Do’s and Don’ts• Replace dust cover and

put up after use• Hold with one hand on

the arm and one on the base

• Only use lens paper to clean microscope lens

• Report any problems to me

• Let the cord hang off the lab table

• Drag the microscope across the lab table

• Try to disassemble the microscope

Calculating Magnification• Two lenses

– Objective lens– Ocular lens (eyepiece)

• Objective lens – Usually 3-4 – Common set: scanning power (4x), low-power

(10x), high-power (40x), and oil immersion (100x)

• Ocular lens – (10x)

• Total Magnification= objective lens magnification x ocular lens magnification

Example Problem 1

Q: If the ocular lens has a power of 10x and the objective lens has a power of 100x, what is the total magnification?

Example Problem 1

Q: If the ocular lens has a power of 10x and the objective lens has a power of 100x, what is the total magnification?

A: Multiply the ocular power times the objective power

10x * 100x=1000x

Total Magnification=1000x

Example Problem 2

Q: If the ocular lens has a power of 5x and the objective lens has a power of 40x, what is the total magnification?

Example Problem 2

Q: If the ocular lens has a power of 5x and the objective lens has a power of 40x, what is the total magnification?

A: Multiply the ocular power times the objective power

5x * 40x=200x

Total Magnification=200x

Preparing a slide

• ((Didn’t use this in class this time, but I figured I’d leave it in))

• To make a temporary wet mount slide– Get a clean slide– Place a tiny, thin piece of the specimen on the slide– Place a small drop of water over the specimen– Place a cover slip over the specimen– For oil emersion put a drop of oil on top of the cover

slip

For this Lab

• Not making a wet mount

• Remember when looking into the microscope to try adjusting the following to get a good view….– Coarse focus– Fine focus– Iris Diaphragm– Position of the slide– Level of magnification