September 20th, 2011
On this day the main goal of the lab period was to stain my environmental and unknown samples to determine their shape. To do this I used the Aseptic technique to transfer each of the samples to a slide for each of them before heat-fixing them. Then I used methylene blue to stain the bacteria for a minute before rinsing off the excess stain and examining them under the microscope. The environmental is a large bacillus that possibly contains spores, while the unknown is a staphalococcus. To prepare for the next lab, I used the Aseptic technique again to transfer each sample to its own Agar tube so I could determine if they were motile or not and to see if they are aerobic or anaerobic.
Environmental Unknown
September 22nd, 2011
On this day I checked my Agar tubes and determined that my environmental was motile since it noticeably spread out from the original streak I made, and I also determined that it was aerobic since it was growing near the top. On the other hand, the unknown is non-motile since it barely moved from the original streak, if it moved at all. It is also anaerobic since none was growing near the surface and seemed to pile up at the bottom. I was unable to make a hanging drop slide since I could not find my broth tubes that contained my bacteria so I prepared new ones for the next day. To practice for my own samples, I borrowed a bit of someone else’s broth to use the Aseptic technique to put a drop on a cover slip and seal it on a depression slide. When I observed their sample under the microscope, I saw bacteria swimming around under the lens. There was also a strange non-motile bacterium that pulsed whenever the swimming bacteria came close to it. I wonder what was going on down there.
Environmenal Unknown
Borrowed Sample
http://www.youtube.com/watch?v=KdEQvIxJHQ8
September 23rd, 2011
To finish the experiment I could not complete yesterday, I prepared hanging drop slides by using the Aseptic technique to transfer the bacteria from their broth tubes to the cover slips that would be used to seal the drops of bacteria (with the help of drops of petroleum jelly on the four corners) in the depression slides. Upon examining the environmental slide, I found that it was motile as it swam around similarly to the bacteria that I borrowed the day before. The unknown, on the other hand, was non-motile since it wiggled around wherever it went and did not “swim.” It was interesting to note that the bacterium was followed around by a train of smaller bacteria. I wonder what purpose that arrangement serves.
Environmental Unknown
http://www.youtube.com/watch?v=evjy7IGHQXU
http://www.youtube.com/watch?v=UEaETLzSh9w
