1. Metric measurement and microscopy

2. The metric system Standard system of measurement in sciences
Length, weight, volume, tempreture

3. Metric units of length
Length: meter (m), centimeter (cm), millimeter (mm), micrometer (µm), nanometer (nm)
1m=100cm
1cm=10mm
1mm=1,000 µm
1µm=1,000nm
1m= 1×102cm= 1×103mm= 1×106 µm= 1×109nm
1nm= 1×10-3µm= 1×10-6mm= 1×10-7cm= 1×10-9m

4. Metric units of length

5. Metric units of length
What is your height?

6. Metric units of weight Weight: gram (g), milligram (mg)
1g=1,000mg= 1×103mg
1mg=0.001g= 1×10-3g

7. Metric units of weight
Using scale to measure the weights of small objectives

8. Metric units of volume Volume: liter (l), milliliter (ml)
1l=1,000ml= 1×103ml
1ml=0.001l=1×10-3l

9. Meniscus Reading

10. Temperature scales Fahrenheit (F) & Celsius (C) C= (F-32°)/ 1.8

11. Microscopy Microscopes Illumination source Magnification
Sliced section image
Three dimension image
Light
microscope
light rays
lower (2000
times)
regular light microscope
stereo-microscope
Electron
electron
beams
higher (over
500,000 times)
transmission
(TEM)
scanning electron
microscope (SEM)

12. Use of the compound light microscope
Pick up the microscope carefully
Never touch the lens with fingers.
Use ONLY lens paper to clean the glass
Don’t loss the key

13. The compound light microscope
Two sets of lenses
—the ocular lenses
—the objective lenses
The light only passes through clear portions, not opaque portions
The objects must be small or thinly sliced sections

14. Total magnification = magnification of the ocular lens × magnification of the objective lens

15. Identifying parts of microscope

16. Focusing the compound light microscope
Always begin focusing with the lowest power objective
Use coarse-adjustment knob ONLY with low-power objective
Make sure the nosepiece is on the lowest power objective when done with the scope assignment
Clean all slides, materials and work area

17. Field of view*
Low-power objective has larger field of view

18. Depth of field*
High-power objective has narrower depth of view

19. Microscopic Observations
Prepared slides
Onion
Euglena

21. Plant cell (root tip cell)
Gills of a fish