This week. Dec 10/12

This week is finally... almost over, along with finals. I am still surprise of how much I've learned in these past few weeks during my internship at the biology lab in Phoenix College. I've learned to do Gram Staining, the methodology behind making media and streaking a plate with a bacteria sample.
Gram Stain is simple and yet easy to mess up, specially when its the first time doing it. After three or four trials I started to get the hang of it. There are four major steps during staining; first crystal violet is applied for 30 seconds, then iodine is added for 60 seconds.  A decolorizer is then added to wash away the crystal violet, if it's a Gram negative bacteria, it will not wash it away if its a Gram positive bacteria. The tricky part with this step is that if the decolorizer is left for too long on, the crystal violet gets washed away from both Gram positive and Gram negative bacteria, but if not left for enough time a Gram negative bacteria might have purple or blue dyed bacteria as well. At the end Safranin is added for about 30 seconds. Between all steps the sample must be rinsed with water for about 5 seconds.
 Just yesterday I was able to perform a Gram Stain on a bacteria that showed antibiotic characteristics. The sample turned out to look like rods which indicates bacili and it was also Gram Positive. The image shows what I saw in the microscope.

I also made my own Macconkey agar, with the instructions of Kimberly, all I know about her is that she works at the lab but I am very thankful. Fun fact, macconkey agar kind of smells like dog food so during the process of making it I remember a German shepherd I had years ago. Hopefully I will be able to use these plates to cultivate some agrobacterium for my research project. Right now I have only written my protocol and cultivated 8 plates with what, after three tests (Gram stain, catalase test and oxidase test, I believe to be Rhizobium. Rhizobium is a plant growth promoting rhizobacteria, or PGPR, that a Gram Negative bacili. It is also positive for a Catalase test and Oxidase test.  I used 4 plates with TSA media and 4 plates with Macconkey media. I have placed those plates in an incubator and I'm just in the waiting processes to see if anything grows, fingers crossed.

Origin of viruses

I came across an interesting article that talks about the origin of viruses. I found this article when I suddenly had the urge of knowing more about viruses; I know that all types of life have DNA in them but then I thought, "viruses have DNA as well." After I had that idea I immediately went online and learned that viruses do not only carry DNA but RNA as well, there is a big mystery behind their origin and not only do they harm humans but they might had a big role to play in the evolution of the three major domains of life, (Archea, Prokaryote and Eukaryote).

Viruses are not living organisms and yet they play a big role in life. The origin of viruses is still being debated today, although three major theories have come to exist. There is a possibility that a virus is the evolution of genetic material moving within a cell, to later on move from one cell to another. Perhaps viruses are descendants of living organisms that opted to become something more simple, purely on the basis of transferring genetic material. There is also the possibility that viruses were first in the big scheme of life; that somehow cellular life evolved thanks to viruses.

Scientists have not come to an agreement as to which theory is correct, if any. Many have come up with different rationalizations to back up their theories but nothing is decisive. Viruses are still a big mystery in the world of science and the more we learned about them the more questions arise. Even after reading this article I still find myself asking "where did viruses come from?" "How can something have the drive to move and replicate without being alive?" I'm not sure if the answers will be revealed during my lifetime but I keep my fingers crossed.

David R. Wessner, P. D. (2010).http://www.nature.com/scitable. Retrieved from 

http://www.nature.com/scitable/topicpage/the-origins-of-viruses-14398218

Telomeres

(Image taken from http://www.cleansingmatters.com/
what-are-telomeres-and-how-can-you-protect-them/)

Have you ever heard of the Hayflick limit? no? Well, there is a certain amount of times that a cell population can divide until the cell division stops. It has been found that human fetal cells in a cell culture will divide between 40 to 60 times. It seems that the reason this happens is because of the shortening of telomeres.

Telomeres are basically a protective layer at the tip of each chromosome. Think of them like the hard plastic at the end of  shoe laces; without it the shoe laces would unravel rather easy. A characteristic of telomeres is that they get shorter each time the cell divides and thus is unable to sustain the chromosome.

There was a team from Harvard Medical School  that wanted to see the impact of telomerase, the enzyme that replaces shortened telomeres, in telomerase deficient samples. To do this they assembled an experiment to see if the reactivation of telomerase would halt or reverse the multy-system regeneration in telomerase-deficient mice. The team from Harvard was able to reverse the aging process of these mice, to be put in overly simplified terms. With their findings they are able to "support the development of regenerative strategies design to restore telomere integrity."

It's interesting to think that we are getting closer to come up with something close to a "Fountain of Youth." This brings out one major moral dilemma, at least for me. Should we even try to make a fountain of youth? What would the implications of increasing life expectancy to an even greater age? Are humans even meant to last longer? I'm sure we will come up with the answers eventually. For now it is very exciting to see the new discoveries in such an important field of Science.

Here is the PDF report for the experiment with Telomerase-deficient mice.

Jaskelioff, Mariela, et al. (2010, November 28). Telomerase reactivation reverses tissue degeneration in aged telomerase-deficient mice. Retrieved from http://natap.org/2010/HIV/telomreverses.pdf