260 likes | 358 Views
Scientific Tools & Techniques. Compound Light Microscope. Uses light Image appears upside down and backwards Under Low Power field of view is larger (4 times) Under High Power field of view is smaller (4 times). How will the f appear in the field of view of a compound microscope?.
E N D
Compound Light Microscope • Uses light • Image appears upside down and backwards • Under Low Power field of view is larger (4 times) • Under High Power field of view is smaller (4 times)
How will the f appear in the field of view of a compound microscope?
FOV in Low Power:4 cells are visibleHow many cells will be visible in high power?
Microscope Rules: • Always start with low power • Field of view is large and bright • Helps you find specimen • Use the coarse adjustment knob to focus
Switch to High Power to see detail • Adjust diaphragm (light) for smaller field of view • Field of view is smaller and darker • Helps see fine detail • Only use fine adjustment knob to focus
Total Magnification: Eyepiece # X Objective # = Total Magnification # • What is the highest total magnification in this diagram? • Answer: 10 X 40 = 400x Eyepiece 10x 40x 10x
What is the total magnification under low power in the diagram? Eyepiece 10x Answer: 10 X 10 = 100x 40x 10x
Electron Microscope • A major breakthrough because they can magnify 250,000 x’s • Shows much more detail than compound light microscopes • Shows great detail of inner structures Ex) The inside of mitochondria in a cell!
Microdissection tools/instruments • Special micro-tools (very tiny) • Used to take apart cells • Ex) Removing a nucleus from one cell and putting inside another cell! • Used in genetic engineering
Use of Staining • Staining allows for cell parts to be seen • The nucleus for example becomes more visible under the microscope when a stain is used • Iodine is often used to stain cells
Centrifuge (Ultracentrifuge) • Spins at high speeds to separate substances by density • Heavier particles end up in the bottom of the test tube
Chromatography • Separates colors • Chromatography paper is used • Ex) Plant pigments can be separated using chromatography
Gel Electrophoresis • Used to separate bands of DNA • DNA bands of different sizes move at different rates • DNA bands move because of the charge • Used in forensic investigation (CSI) • Also used to determine paternity
Gel Electrophoresis • How do you know these samples are from different people? • What’s responsible for the movement of DNA?
Which direction should the slide be moved to center the cell?
The diagram below shows the letter h under low power, which diagram shows the high power field of view? 1. 2. 3. 4.
In which direction should the slide be moved to center the cell?
Which lab technique was used to separate the substances in the test tube?