Slide preparation 2

You have now prepared the microscope slide taking extra care not to trap any bubbles in the specimen. 

Professor Johnson demonstrates the appropriate way of focusing on the sample: 

1. Turn on the light and adjust the intensity using the dimmer.

2. Lower the stage using the coarse focus knob. 

3. Begin observation using the lowest magnification objective lens (e.g., 4x or 10x). 

4. Place the prepared microscope slide on the stage of the compound microscope. 

5. Use the coarse focus knob to bring the specimen into rough focus i.e until light is shining through it. 

6. Use the fine focus knob to achieve a clear image. 

7. Begin by examining the entire slide under the lowest magnification setting to gain an overall perspective before transitioning to higher levels of magnification.

8. Switch to the 10x objective lens. If the slide is in focus at 4x magnification, it should remain relatively focused when switching to 10x. Fine adjustments using the focus knob may be needed to achieve optimal clarity. If the specimen becomes entirely out of focus, return to the 4x.

9. Use the 40x / 100x objective lens if you desire greater detail. The choice of magnification depends on the sample you are trying to observe.

• Unlike the other objectives which function optimally in air, the 100x objective lens requires immersion oil to focus correctly.

10. Once you finish switch back to the 4x magnification, dimming the light completely before turning it off, and lowering the stage. Ensure there are no slides left on the stage before storing the microscope.

What is the best objective to observe your specimens?