Monthly Archives: December 2015

A Closer Look

This week we’re using microscopes to observe microorganisms in pond water.

Day 1:

 Today, we worked on getting affiliated with the microscopes, and practiced preparing wet mounts using newspaper clippings. 

  

 
First, we set the microscope to it’s lowest objective (4x) for a total magnification of 40x including the eyepiece. We viewed a ruler under the microscope, and found the field of view to have a diameter of 5 mm (or 5000 μm). Next, we practiced making wet mounts. We cut out a tiny c from a newspaper, and set it on a glass slide. Then, we added a drop of water, and allowed it to soak the paper. We then covered this all with a plastic cover. Our overall result?

   
As you can see, the opposite side of the paper was a colored picture. Because our slide was backlit, we were able to see the ink on both sides. We noticed CYMK dots used to print different colors but too small to see normally. Here are the rest of our observations

  Tomorrow we can examine and identify various microorganisms in pond water with microscopes, and put the skills we learned today to use.

Day 2:

Today we viewed pond water in wet mounts to search for microorganisms. Although we were not able to confirm with our teacher if there really were any specimens in our sample, we found some interesting observations.  
  

Here we found what may have either been air bubbles trapped within the mount, or else a colony of algae (chlorophyceae, although we doubted this due to a lack of visible chlorophyll).

  

Next, we examined two brown strands of our own hair.  Though it was difficult to snap a picture of it, we noticed that each strand was actually semitransparent, and was dotted by darker pigments along the very center.

 

Finally, we moved on to the analysis of our experiment. We noticed that as we increased the zoom, our field of view shrunk in an inverse relationship. We also noticed that because the objects we viewed were three dimensional, we could only focus on one layers of them at a time using a high-power objective. Hopefully, we will be able to continue to use the processes with the microscopes to observe more organisms throughout the year.

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