September 6, 2018

Biology Lab 3

Rationale: The purpose of this experiment is to understand how a compound microscope works and understand all of the other complimentary tools such as slides, cover slips and pipettes. We also used this time to calculate the field of view for each of the magnifications on the microscope. Then also, we used this lab to take a closer look at ciliates from last class and the different methods there are to observe these organisms.

Methods done:

1. Take out both the compound microscope and the dissecting microscopes and ensure that they are both in working order by plugging them in and ensuring the bulbs are in working order and the focusing systems are in check.
2. To measure the distance of the field of view for the microscope you are using, place a clear ruler on the stage and place the microscope on the lowest magnification.
3. Count how many millimeters you are able to see in the oculars.
4. Using the equation: Magnification (low) x Field of view (low) = Field of View (high) x Magnification (high) to calculate the length of the field of view for each of the magnification on the compound microscope.
5. Once the calculations were done for each of the magnifications, take the ruler from the stage.
6. Take the tray with the samples of ciliates and place them under the dissecting microscope and examine each of the spots on the tray to determine which sample you would want to observe under the compound microscope.
7. Once you find the sample you wish to view, using a pipette, take a small sample and place a tiny dab of the sample on a cover slip.
8. Take the coverslip and a concave slide and place the dab of the sample in the concave area by placing the coverslip and the concave slide together.
9. Place the slide into the stage of the compound microscope and view the ciliates using the lowest magnifications as the ciliates will most likely be moving and will be hard to track and view under higher magnifications.
10. To view the samples at higher magnification, a dye will be needed.
11. Perform step 7 once again.
12. Place a small sample of iodine on a flat slide.
13. Place the small dab of ciliate into the iodine, which will kill the sample and allow for the researcher to get a closer look at the organism without it swimming away. The dye of iodine also outlines the organism more to allow for better observation.
14. When the ciliates have been observed, take the slides and the cover slips used and clean them properly with the correct cleaning solutions, dry them and set them back into their respective cases.
15. With both of the microscopes used, ensure that the bulbs are turned off and the microscopes are unplugged, wrapping the power cord around the arm and placing the protective wrap over the microscopes.
16. Ensure that your workspace is cleared and clean from any debris that may have accumulated over the time of you working.

Findings:

In the experiment, we calculated the diameter of the compound microscope and the above table shows the calculated figures. Then also, we did view ciliates under the compound microscopes, first looking at them in their alive state in the concave slides. We decided as a team to view sample #2. This showed a few key characteristics about the organism, including the general structure and the swimming method that the organism uses. This was at a very low magnification as the organism would have been too fast to keep track of at higher magnifications. To get a closer look at the organisms and a more detailed picture of their structure, we used the iodine dye to outline their structure. However, we had difficulties locating the organisms in this sample and the team was not able to look at the organisms in more detail under higher magnifications. This experiment taught myself and my team the uses of a compound microscope and how they are useful in the lab and in experiments.

Further studies with this experiment could include looking at other samples of ciliates and how their swimming methods compare and how that could potentially be beneficial based on the organism’s natural habitat.