Download Worksheet on Magnification and Resolution Feb, 2009 Due

 Name: __________________ Bio29 Lab 1: Worksheet on Magnification and Resolution Feb, 2009 Due: At the start of lab, one week from your discussion section meeting NOTE: To be comfortable with microscopy and cell biology, you should achieve instant recall of the following relationships: 1 mm (millimeter) = 0.001 m (10‐3 m) ‐6
1 μm (micrometer) = 0.001 mm (10 m) 1 nm (nanometer) = 0.001 μm (10‐9 m) 1 Ǻ (Ǻngstrom) = 0.1 nm (10‐10 m) 1. A certain ciliate has contains fine vacuolar structures within its cells, these appear as spots approximately 0.4µm apart. If this protist is visualized under the 40X objective lens with a 10X ocular, how far apart would the dots appear in the final image (in mm)? Show your calculations. 2. The numerical aperture of your 40X objective is 0.65. Assume you are using violet light with a wavelength of 410nm. Use the Abbe equation to calculate the resolving power D, in µm of which this objective is theoretically capable. Show your calculations. 3. Is this objective able to resolve the spots in the cliate in question 1? Explain. 4. The human eye has a resolving power of approximately 0.18mm. With the above combination of 40X objective and 10X ocular, would you be able to resolve the spots in question 1? Explain. Name: __________________ 5. What if you used an 100X objective and 10X ocular? Show calculations. 6. What if you used the 40X objective and a 3X ocular? Show calculations. 7. The endoplasmic reticulum in a mammalian cell is made up of tubules about 100‐
200nm in diameter. In order for the human eye to resolve these tubules would a 40X or 100X objective be sufficient (assume a 10X ocular)? Show your calculations 8. Which of the following, when used for sample illumination, would allow the highest resolving power? (circle) Green light Red light Orange light 9. Extreme halophilic archaea are prokaryotes that grow on up to 10M NaCl. Individual cells are about 1µm in diameter. What is the minimum total magnification (objective plus ocular) would you seek in order to resolve these cells? 10. Does depth of field increase or decrease as you increase magnification? (hint: as you increase magnification how much can you change the fine focus and still keep parts of the image in focus ?)