lab pro - metric system and mircoscopy

to convert to a smaller unit, move the decimal to the …

right ; multiply by the difference in magnitude

to convert to a larger unit, move the decimal to the …

left ; divide by the difference in magnitude

mechanical stage

moves the stage back and forth, left and right

coarse and fine focus knobs

focus on objects

substage condenser

2 lenses that focus light from light source on the object

aperture diaphragm

controls amount of light illuminating object

ocular lens

usually 10x magnification

objective lenses

4x: scanning

10x: low power

40x: high-dry

50x: low oil immersion

100x: oil immersion

total maginification

(ocular lens) x (objective lens mag) = total magnification

how are dilutions expressed?

as ratios

a 1:10 dilution is how many parts sample to water?

1 part sample : 9 parts water

what is the equation for finding diameter or total magnification on high or low power?

DHP = (DLP) x (MLP) / MHP

can be rearranged to find different variables

calculating size of objects

1. confirm objective lens mag.

2. assess shape of object (round or ovular)

3. estimate how many times object fits in field of view

4. calculate size by dividing from FOV