Microscopy Tips

Last week, I went back into my first successful trial and tried to score the the slides using fluorescent microscopy. I found that most of the cells on my of my slides are now gone and that the slide could no longer be scored. I recall that when I first viewed this slide under the microscope last week, it took a few minutes for the camera to snap a picture. The reason for this is that the images that I was seeing in the camera driver is now real and was not visible with the naked eye. The time that was required to snap a picture of my slide had caused my fixed cells to become photobleached. This is extremely disappointing, because the successful trial cannot yield satisfactory data for my project. Despite this, I am now aware of a new microscopy tip. Since pictures can be taken at any time, I should score my slides as soon as possible and wait to take the pictures later. At this point, I plan on repeating this trial in order to score the cells and get a good sense of how MK-STYX is causing HeLa cells to respond to stress (serum-starve).

Diatoms

In addition to geochemical changes within my lake cores, I am attempting to analyze biological changes within my sediments in the form of diatoms. Diatoms are siliceous algae which can be identified and analyzed under a microscope. These tiny, single-celled organisms are abundant in these lake sediments and different species prefer different aquatic environments. Thus, by identifying different diatom species at different depths in my cores, I hope to develop an additional line of evidence for different depositional environments (freshwater, marine).

[Read more…]

Using the Element Analyzer

After completing initial assessments of my cores, the next step in lab work was sampling each core for analysis in the Element Analyzer. This instrument combusts a small sample of dry sediment, passing the gasses through a series of chambers in order to analyze the gasses for percentages of Carbon, Nitrogen and Sulfur. With these percentage results (in addition to Carbon to Nitrogen ratios), geochemical changes related to changes in depositional environment are often apparent. Sulfur can be particularly useful since it often tracks changes from marine to freshwater inputs, where higher Sulfur levels are likely marine.

[Read more…]