How to Operate the Light Microscope

2. HOW TO OPERATE THE MICROSCOPE

1. Place the microscope on a flat surface and make sure that the microscope power switch is in the off position and brightness control dial at the lowest setting. Plug the power cord and turn on the switch from the wall socket.

2. Lower the mechanical stage to the lowest position by turning the coarse adjustment knob. Then turn the revolving nosepiece until the scanning objective (4X) is rotated into position.

3. Turn the coarse adjustment knob until you get the stage to the highest position. You know that the stage is at the highest position when you can no longer turn the coarse adjustment due to limit stop.

4. Turn the condenser control knob or lever until you get the condenser at the highest position.

5. Turn the horizontal lever of the iris diaphragm all the way to the right (the smallest opening).

6. Securely place the microscope slide with the specimen on the stage by opening the jaw of the slide holder. Then, turn the stage control knobs and bring the specimen to the center of the opening in the stage directly over the light source.

7. Double check the light intensity at the lowest setting and turn on the microscope using the microscope switch. Then turn the light intensity control dial to the medium setting.

8. Now looking through the eyepiece, turn the coarse focus knob carefully, and slowly move the stage away from the lens until you get your specimen into focus. Then turn the fine adjustment knob until you get a sharp image. Scan the slide and select the part of the specimen you are interested in and center it in your field of view.

9. If you want to observe the specimen under 10X objective, turn the revolving nosepiece and bring the 10X is rotated into position.

10. Use ONLY the fine focus adjustment knob to focus the specimen.

11. You may need to open iris diaphragm to match with NA of the objective lens and increase the brightness of the light source to optimize the illumination. In general, the higher the power, the more light you require.

12. Repeat with the high power 40x objective, adjusting the iris diaphragm if required. Use ONLY the fine adjustment knob to focus the specimen.

13. When you are done with observing the specimen. Lower the stage. Turn the revolving nosepiece until the scanning objective (4X) is rotated into position and remove the slide. NEVER attempt to remove the slide while you are using the high power objectives. If you do so, slide or cover glass may scratch the objective lenses.

14. When you are done using the microscope, make sure to turn the brightness control dial to the lowest setting before turning off the microscope.

15. If you have anything spilt on the stage, clean the stage with a piece of tissue paper. Clean the objective lenses with a piece of lens paper to wipe off any moisture or dirt. DO NOT use tissue or cloth to clean the ocular or objective lenses.

16. Unplug the power cord and securely store the microscope.

How to use the Oil Immersion lens

1. Follow the above steps from 1 through 12 for dry objective focusing and center a recognizable object in the center of the field of view.

2. Lower the stage and rotate the revolving nosepiece so that a midway position is obtained between the 40x objective and the 100x objective.

3. Place a small drop of immersion oil (Canada Balsam, Immersion oil type A, Cedarwood oil, etc.,) onto the cover glass, while observing the illumination spot. Make sure not to introduce air bubbles. Sometimes specimens are fixed or heat fixed and stained without a coverslip (e.g. bacteria smears, blood smears, sputum, stool smears, etc.,). In such situation, immersion oil is directly placed on the specimen.

4. Rotate the nosepiece until the oil immersion lens is rotated into position.

5. By looking from the side, slowly elevate the stage back up using the coarse adjustment knob until you see the oil immersion lens get in contact with the oil drop. When the objective contacts with oil, there will be a small flash of light as the drop of oil change shape.

6. Make sure that there is no air gap present between the cover glass /specimen and the front lens element of the oil immersion objective.

7. Use ONLY the fine adjustment to obtain a sharp image. Adjust the light with the iris diaphragm if required.

8. DO NOT Switch back to 40X dry lens, as dry lenses are not sealed properly to keep out the oil. If oil gets into the dry lenses, it is impossible remove the oil and can damage the lens.

9. After you finish using the oil immersion lens, lower the stage and wipe off the oil on the front lens element of the oil immersion lens using a lens paper. DO NOT use the same lens paper to clean the 40X . By doing so, you may accidently transfer oil on to the 40 X. Remove any residue oil from objectives using small a amount of chloroform applied to a piece of lens paper.

3. HOW TO CARE FOR THE MICROSCOPE

• Do not handle the microscope with wet hands

• Always carry the microscope with both hands. Always lift the microscope by the arm of the microscope and keep one hand under the base.

• Always start observations with the low power objective lens.

• When using high power objectives, use the fine focus knob to focus the specimen, never use the coarse focus.

• Do not touch the lens elements of any lens.

• Do not let immersion oil get in contact with dry lenses.

• When you are done using the microscope, use a lens paper to clean lens elements. Use a clean soft cloth or tissue to clean the stage of the microscope. Wrap the electrical cord securely around the microscope’s arm, and return your microscope to its storage area.