Dead or Alive Results
BIOSC 0050
Oct. 9, 2012
Dead or Alive? (Week 2) Post-Lab Assignment
Results:
The results of the Feulgen’s Schiff’s Stain test are that samples ALV-188-23 and ALV-843-20 turned magenta and samples ALV-882-21 and ALV-694-02 did not turn magenta. The result of the tetrazolium test is that all four of the samples did not turn pink. We were not able to conduct the detailed analysis of cultured plates with growth, so not results are available for this test.
Discussion:
For the Feulgen’s/Schiff’s Stain that tests for DNA, the samples that contain DNA will show up under a compound light microscope as a magenta color while samples that do not contain DNA will not show up as magenta. A sample of bacteria from an agar plate was used as a control for the DNA test, and it showed up as magenta from the Feulgen stain; this confirms that the test accurately indicates the presence of DNA. The results show that samples ALV-188-23 and ALV-843-20 contain DNA, which means that the samples are organisms that are either alive or once living, according to the test. Also, the results show that samples ALV-882-21 and ALV-694-02 do not contain DNA, so these samples were never alive.
The tetrazolium test indicates the presence of redox reaction, which signifies metabolic activity by turning samples that perform metabolism a pink color. Sucrose was used as a control to show that the test is accurate in that it does not turn samples that do not perform metabolism pink. Sucrose was not turned pink, which validates the accuracy of the tetrazolium test. As expected, samples ALV-882-21 and ALV-694-02 did not turn pink; the Feulgen’s/Schiff’s Stain that was done previously showed that samples ALV-882-21 and ALV-694-02 were never living, so it makes sense that they would not have any metabolic activity. Since samples ALV-188-23 and ALV-843-20 did not turn pink, yet contain DNA, we conclude that these two samples are organisms that are now dead.
We were not able to conduct the detailed
Oct. 9, 2012
Dead or Alive? (Week 2) Post-Lab Assignment
Results:
The results of the Feulgen’s Schiff’s Stain test are that samples ALV-188-23 and ALV-843-20 turned magenta and samples ALV-882-21 and ALV-694-02 did not turn magenta. The result of the tetrazolium test is that all four of the samples did not turn pink. We were not able to conduct the detailed analysis of cultured plates with growth, so not results are available for this test.
Discussion:
For the Feulgen’s/Schiff’s Stain that tests for DNA, the samples that contain DNA will show up under a compound light microscope as a magenta color while samples that do not contain DNA will not show up as magenta. A sample of bacteria from an agar plate was used as a control for the DNA test, and it showed up as magenta from the Feulgen stain; this confirms that the test accurately indicates the presence of DNA. The results show that samples ALV-188-23 and ALV-843-20 contain DNA, which means that the samples are organisms that are either alive or once living, according to the test. Also, the results show that samples ALV-882-21 and ALV-694-02 do not contain DNA, so these samples were never alive.
The tetrazolium test indicates the presence of redox reaction, which signifies metabolic activity by turning samples that perform metabolism a pink color. Sucrose was used as a control to show that the test is accurate in that it does not turn samples that do not perform metabolism pink. Sucrose was not turned pink, which validates the accuracy of the tetrazolium test. As expected, samples ALV-882-21 and ALV-694-02 did not turn pink; the Feulgen’s/Schiff’s Stain that was done previously showed that samples ALV-882-21 and ALV-694-02 were never living, so it makes sense that they would not have any metabolic activity. Since samples ALV-188-23 and ALV-843-20 did not turn pink, yet contain DNA, we conclude that these two samples are organisms that are now dead.
We were not able to conduct the detailed