1. Microscopy Notes

2. I. Introduction A. Compound microscopes contain a number of lenses: 1. 10 x eyepiece 2. 4 x objective 3. 10 x objective 4. 40 x or 45 x objective 5. and sometimes a 100 x objective for oil immersion.

3. B. The power of the microscope can be calculated by multiplying the eyepiece X the objective lense. Example: 10x eyepiece X 100x objective = 1000 times normal eyesight.

4. C. Definitions 1. Resolution: the microscopes’ ability to distinguish between 2 points that are close together. The resolving power is expressed in length. 2. Oil immersion this objective uses immersion oil to allow light to pass through it the same way light passes through the glass slide. The oil decreases the bending of the light rays allowing more light to pass directly to the specimen.

5. 3. Monocular: a microscope with only 1 eyepiece. 4. Binocular: a microscope with 2 eyepieces as opposed to one eyepiece. Most hospital laboratories use binocular microscopes.

6. base Revolving nosepiece objective Stage clips Iris diaphragm bulb lamp On/off switch eyepiece arm Mechanical stage Coarse adjustment knob Fine adjustment knob Monocular tube

7. II. The Use of the Microscope A.Lower the stage to its lowest position using the coarse focusing knob. Always start with the lowest power objective. B.Place the slide on the stage and place the stage clips on top of the slide to hold the slide in place. C.Use the coarse adjustment knob to focus on the slide, and then use the fine adjustment knob until the object is in sharp focus.

8. D. Adjust the light intensity by raising and lowering the condenser to give the best image. E. After focusing with the coarse objective, rotate the next higher objective into the position over the slide. Continue to rotate to the next higher objective until you are on the 100 x objective. Use only the fine adjustment knob to obtain a sharp image.

9. F. Oil Immersion 1.Rotate the objectives so that there is NOT a lens directly over the slide. 2.Place 1 drop of the immersion oil on the slide over the specimen. 3.Slowly rotate the 100 x objective into position over the slide. 4.Use only the fine adjustment knob to focus on the specimen slide. 5.Adjustment of light intensity may be necessary.

10. G. To change slides during the investigation, follow steps A through F. H. At the conclusion of the laboratory investigation, lower the stage to the lowest position. I. Clean all lenses and place the 4 x objective in position.

11. J. Wrap the cord around the arm of the microscope and replace the dust cover. K. Carry the microscope back to the microscope cabinet by holding it by the arm and base.

12. Exit Ticket What is the name of the equipment in the picture? What is its use? What objective lens do you use for oil immersion? Do you use the fine or coarse adjustment knob at that power?