Thursday, September 16, 2010
DNA Extraction Results
On Tuesday, September 14th our class did our DNA extraction lab. After completing all the steps in our lab, we were able to isolate the DNA in the center of our test tubes. We revealed what looked like a floating, clear, stringy substance. After letting the DNA sit for 5 minutes, we inverted the test tube and the DNA strung itself out and we were able to see the double helix shape of the genetic information! This real life encounter with the building blocks of our beings was incredible to see, and to make it all the more better we got to take our DNA home in a necklace! This lab let us see the amazing and unique shape of DNA that is located inside every single one of our cells.
Wednesday, September 15, 2010
Cheek Cell DNA Extraction
Our second lab of the year is designed to teach us about our DNA. In the lab we will actually extract our own DNA and put in a bottle to attach to a necklace!
DNA is present in all living things, it is the "carrier of all genetic information" and it determines everything about you. It also carries instructions to tell your cells what to do, and how to do it. In this lab our goal is to precipitate the DNA in order to be able to see it by itself, and therefore futher our understanding of this tiny thing that has quite a bit of power over our bodies. From what we know from scientists, DNA is in the form of a twisted stairway type of structure. The each "step" of the stairway is made up of bases, there are four of them named, adenine, guanine, thymine, and cytosine. Each of the bases is connected to one sugar and a phosphate group, the full grouping of a base, sugar and phosphates, create the backbone of the DNA. The bases are organized so that they each base pairs up with one other base, adenine with thymine, and cytosine with guanine. The reason for the matching of the bases are because they make messages that can be understood by genes (inside the cell), and then the genes send the information to the proteins which control the basis for the body's structure and function.
In this lab, the first step we will be taking is we will loosen our cheek cells by chewing on our cheeks, then we will use a saline solution (0.9 % salt water) to swish around our mouths, after 30 seconds we will replace the contaminated water back into the cup in order to create a funnel into a test tube to consolidate our salt water now ridden with cheek cells. The reason for using saline solution is to neutralize the DNA and make it hydrophobic (water-hating). Next we will add a lysis buffer to break down or dissolve the cell membranes in our cells, and then we will add 100 mL of protease to break down the proteins. After those steps we gently invert our test tubes, to mix up the solution. In addition to all these chemicals, next, we will put our text tubes in a water bath of about 50 degrees celsius for ten minutes to speed up the reaction. The last thing we will do is add 5 mL of cold ethanol. After doing this procedure, we should be able to see our DNA consolidated in the center of our test tube, revealing the most important piece of genetic makeup for our body!
DNA is present in all living things, it is the "carrier of all genetic information" and it determines everything about you. It also carries instructions to tell your cells what to do, and how to do it. In this lab our goal is to precipitate the DNA in order to be able to see it by itself, and therefore futher our understanding of this tiny thing that has quite a bit of power over our bodies. From what we know from scientists, DNA is in the form of a twisted stairway type of structure. The each "step" of the stairway is made up of bases, there are four of them named, adenine, guanine, thymine, and cytosine. Each of the bases is connected to one sugar and a phosphate group, the full grouping of a base, sugar and phosphates, create the backbone of the DNA. The bases are organized so that they each base pairs up with one other base, adenine with thymine, and cytosine with guanine. The reason for the matching of the bases are because they make messages that can be understood by genes (inside the cell), and then the genes send the information to the proteins which control the basis for the body's structure and function.
In this lab, the first step we will be taking is we will loosen our cheek cells by chewing on our cheeks, then we will use a saline solution (0.9 % salt water) to swish around our mouths, after 30 seconds we will replace the contaminated water back into the cup in order to create a funnel into a test tube to consolidate our salt water now ridden with cheek cells. The reason for using saline solution is to neutralize the DNA and make it hydrophobic (water-hating). Next we will add a lysis buffer to break down or dissolve the cell membranes in our cells, and then we will add 100 mL of protease to break down the proteins. After those steps we gently invert our test tubes, to mix up the solution. In addition to all these chemicals, next, we will put our text tubes in a water bath of about 50 degrees celsius for ten minutes to speed up the reaction. The last thing we will do is add 5 mL of cold ethanol. After doing this procedure, we should be able to see our DNA consolidated in the center of our test tube, revealing the most important piece of genetic makeup for our body!
Tuesday, September 7, 2010
Yogurt Lab Discussion....
On Wednesday, June first, our class started the Yogurt Lab. We began with four test tubes...
The first had only milk in it (negative control), the second had milk and yogurt (positive control), the third had yogurt and ampicillian and the last contained E.coli.
After the first three test tubes were inoculated with a pure culture of suspected pathogen using an "inoculation loop", and the E.coli was inoculted with the E.coli pathogen, we mixed them up using the vortex, which we all had fun with! The next thing we did was to make sure everything was labeled and then we put them in the water bath at 37 degrees celsuis, in order to keep them at a constant warm temperature to maximize our results,and to see how the bacteria progressed when we returned the next morning,
Results: The next day.... We removed the test tubes from the water bath and looked at our changes. The first test tube (with only milk) had a chunky white formation at the top and a clear liquid throughout, the milk had, as a general defintion, curdled. The second test tube, with milk and yogurt had a white fluid, the third (yogurt and ampicillian) was a clearish liquid. I predict the reason that no solid was formed was because ampicillian is a beta-lactum antibiotic, which attacks the cell walls of bacteria, not allowing them to continue their growth. The last test tube had E.coli in it, this tube was the tube that by looking at it, you knew it smelled and we each bravely smelled it, determining the foul smell of rotten eggs. This test tube was a milky liquid also. After this we tested each tubes ph;
#1-ph 6
#2-ph 6
#3-ph 7
#4-ph 6
Our control test tube, containing the yogurt had a ph of 4.
A video of our results/procedure in action is below:
http://www.youtube.com/watch?v=vVhIArPkyi0
By infecting each tube with bacteria, we found out that the "yogurtness" disease could be spread through contact with the bacteria.
Possible sources of error, a substance not being infected by the yogurt enough, a temperature issue involving the water bath, and an incorrect reading of the substances ph, could all contribute to errors in the experience.
The first had only milk in it (negative control), the second had milk and yogurt (positive control), the third had yogurt and ampicillian and the last contained E.coli.
After the first three test tubes were inoculated with a pure culture of suspected pathogen using an "inoculation loop", and the E.coli was inoculted with the E.coli pathogen, we mixed them up using the vortex, which we all had fun with! The next thing we did was to make sure everything was labeled and then we put them in the water bath at 37 degrees celsuis, in order to keep them at a constant warm temperature to maximize our results,and to see how the bacteria progressed when we returned the next morning,
Results: The next day.... We removed the test tubes from the water bath and looked at our changes. The first test tube (with only milk) had a chunky white formation at the top and a clear liquid throughout, the milk had, as a general defintion, curdled. The second test tube, with milk and yogurt had a white fluid, the third (yogurt and ampicillian) was a clearish liquid. I predict the reason that no solid was formed was because ampicillian is a beta-lactum antibiotic, which attacks the cell walls of bacteria, not allowing them to continue their growth. The last test tube had E.coli in it, this tube was the tube that by looking at it, you knew it smelled and we each bravely smelled it, determining the foul smell of rotten eggs. This test tube was a milky liquid also. After this we tested each tubes ph;
#1-ph 6
#2-ph 6
#3-ph 7
#4-ph 6
Our control test tube, containing the yogurt had a ph of 4.
A video of our results/procedure in action is below:
http://www.youtube.com/watch?v=vVhIArPkyi0
By infecting each tube with bacteria, we found out that the "yogurtness" disease could be spread through contact with the bacteria.
Possible sources of error, a substance not being infected by the yogurt enough, a temperature issue involving the water bath, and an incorrect reading of the substances ph, could all contribute to errors in the experience.
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