Friday, November 19, 2010

Discussing The Strategic Use Of Microarrays In The Study Of Lung Cancer Genes

A) Results: From the gene chip our lab group was able to determine that: Genes 1, 2, and 5 were active in in the cancer cells, Genes 2,3, and 6 were expressed in cells obtained from healthy tissue, and also that Gene 4 was express in neither the healthy cells nor the cancerous cells. We were able to tell this becauseof the colors of each gene on the slide. Genes 1 and 5 were pink (pink means expressed only in cancer), Genes 3 and 6 were blue (blue means only expressed in healthy cells) , Gene 2 was purple (this represents expression in both healthy and cancerous), and Gene 4 was clear (expressed in neither).

B) Sources of Error:
- Not enough of the cDNA was added, and the true color of the gene was not shown.
- The genes from the gene chip were not accurate, and we tested the expression of the wrong gene.
- We pipetted too much of the cDNA, and the slide overflowed, thus we were unable to get an accurate reading of the expression of the certain gene.
- We left the gel in the pipette for too long so it hardened and less than 20 microliters was exposed to the slide.

Monday, November 15, 2010

Translating Diseases; The Strategic Use Of Microarrays In The Study Of Lung Cancer Genes

A) Microarrays have simplified how scientists study gene expression in thousands of cells. This new technology detects patterns in transcription and translation, and aids in the understanding of the normal and abnormal aspects of cell function. The process of using Microarrays to analyze/study genes involving lung cancer include: creating a DNA chip, and using the DNA chip to analyze complementary DNAs isolated from both cancerous and noncancerous tissue (the same tissue). The Microarray will then indicate the differences between the two corresponding genes. This will be an indication of the extent to which transcription occurred. Some scientists have indeed observed that some genes are not transcribed as much in cancer cells as in healthy cells, and that some genes are not transcribed as much in healthy cells as in cancer cells.

B) The purpose of this experiment is for our lab table to use Microarrays to study Genes Involved in Lung Cancer. This will hopefully give our group a better understanding of the causes of the disease on a genetic level, and thus allow us to speculate with possible methods to prevent or cure it.

C) In this experiment, our lab table will be studying six genes using a Microarray. We will prepare the Microarray by spotting six different gene sequences onto a glass slide. Then we will obtain DNA tubes from a 70 degree water bath, and spot the appropriate gene solution onto the correct areas of out slide. To hybridize the Microarray, our group will add fifteen microliters of hybridization solution to each spot. We will then wait and observe our results when they appear.

D) Although we have the six genes that we are to study, making predictions is not possible because we do not have the background knowledge to hypothesize our results. However, I am quite certain that our group will accomplish something worthwhile, and we will learn valuable facts about gene expression and the effects of cancer on this.

Monday, November 1, 2010

The Sticky Ends Justify The Means Discussion

A) During Day one of the lab, our lab table acquired the DNA of the five suspects, and the DNA found at the crime scene. The purpose of the experiment was to identify the culprit by matching the DNA found at the scene with the DNA of the five suspects using Restriction Fragment Length Polymorphism. After acquiring the DNA, we added restriction enzymes to the tubes, flicked/tapped them, and placed them in a hot water bath for 30 minutes. On Day two we ran the newly cut DNA through a gel, and visually compared the samples using loading dye to stain the DNA (make it visible), and attracting the fragments to the positive end through Gel electrophoresis. Gel electrophoresis functions by pulling fragments of DNA (negatively charged) through the gel matrix towards the red end (positive), run to red. On Day three, our group was able to compare the DNA of the five suspects with the DNA found at the crime scene. We were able to positively identify Chloe Krey as the culprit in this crime scene.

B) Possible Sources of Error:
- We did not add enough loading Dye so the DNA fragments were not visual.
- Accidentally scraped off a skin cell into a test tube, and my DNA was analyzed instead of a suspect's DNA.
- We did not add enough DNA to the tube, and thus not enough substance was present for DNA to become fully visible.
- Accidentally added the wrong suspects DNA into the wrong well, and the wrong suspect was 'proven' guilty by the DNA evidence.
- Accidentally added the food coloring in place of the Loading Dye, and the DNA was not properly stained thus leading to an inaccurate reading.