Introduction

Lab: DNA Chips: Genes to Disease
Using Microarrays to Study Genes Involved in Lung Cancer

Background: Microarray help to accelerate scientists in their research. This enables scientists to look at more then one type of cell or cells. A DNA chip, microarray, gene chip, and genome chip are all terms that describe a solid matrix, like a glass slide, that has arranged spots, each a copy of a specific oligonucleotide representing part of a genome. Analysis of a DNA chip shows genes that were transcribed in the cancerous tissue and which in the normal tissue, and indicates which genes might be important in the development of cancer. One microarray can contain more than 30,000 spots of DNA, each representing a different gene in an organism.

Discussion!

When we got the finished results from the gel, the results showed that the person responsible was suspect 2 aka Katie Records. Her DNA matched the DNA from the crime scene. The only mistake we might have made was not going deep enough in the gel while injecting the DNA.

Introduction!

Technicians in forensic labs are usually asked to do DNA profiling or "fingerprinting" to help or analyze a case for law enforcement or other uses. DNA profiling is a technology based on detecting differences in the repeat copy number. Patterns of produced samples represent DNA taken at the scene of the crime. The restriction enzyme can be used to cut DNA isolated from any source. Agarose gel electrophoresis separates DNA fragments by size. The evidence needed for DNA fingerprinting can be obtained by biological material such as: body tissues, body fluids (blood and semen), hair follicles, even dried blood stains or mummified tissues. The restriction enzyme works best under a specific buffer and temperature conditions. In our lab- CSI: AHS or 94549; we will be using the restriction enzymes to cut DNA palindromes. RFLP stands for Restriction Fragment Length Polymorphism. We will cut DNA and generate fragments of different length-"run a gel"; crime scene-"run to red"; DNA from suspects.

DNA Extraction Lab

DNA is responsible for all life. DNA has four important bases: thymine (T), adenine (A), cytosine (C), and guanine (G) which forms a double helix. DNA has 3 cycles, replication, transcription, and translation. In this lab we will be extracting our DNA from our cheek cells. We have to loosen our cheek cells and swish saline in our mouth and awkwardly spit it into our test cup, and then transfer it into our test tubes. Then we add 2ml of lysis buffer, then add protease to the test. After that we invert the tube and then place it into the incubator. After 10 minutes, apply cold alcohol. When the DNA appears, we extract it from the tube and put in the vial.

Discussion!

Upon returning to our lab table with our incubated samples, we observed that the tubes did not look any different from yesterday. We then got a closer look and still the tubes look exactly like they did yesterday. Each of us smelled the tubes and found that tube 1 smelled slightly like milk, tube 2 smelled like yogurt, tube 3 smelled slightly like milk, and tube 4 smelled slightly sour. All four tubes were white, and their texture was liquid. Tube 1 had a pH of 6, tube 2 had a pH of 6, tube 3 had a pH of 7, and tube 4 had a pH of 7. Then we testes the control yogurt cup, which was thick in texture, white, smelled like yogurt, and had a pH of 4. I think if the the tubes had more time to incubate, there would be better results. Maybe our lab group did not put enough e. coli into tube 4.

Yogurt Lab Procedure!!

In this lab we will be making yogurt! To start this lab, we need will need to procure four test tubes with milk inside them. Then we are to label the test tubes negative, yogurt with amp, positive and e. coli. Each will have the following added to the test tubes which will then be mixed in the vortex. Once mixed, the tubes will be placed in an incubator for 24-48 hours. Lastly, once the samples have been incubated, we will        examine and observe what has happened and record the results.

Yogurt Lab

Bacteria was not well known around the 1800's. Many people were getting sick and dying, which raised a few eyebrows. German physician, Robert Koch, used postulates which were a series of tests created to prove the existence of microbes. There are three main types of bacteria, coccus which is spherical, spirillum a spiral shape, and bacillus which is rod-shaped. Bacteria multiply using binary fission. Some bacteria have thick cell walls which make a dye called Gram stain, these are known as Gram-positive bacteria. The other bacteria have thin cell walls that do not absorb the dye and these are known as Gram-negative bacteria. Bacteria use enzymes to break down sugars chemically, this process of bacterial metabolism is called fermentation. Lactic acid is the waste product from lactic acid bacteria. Lactic acid lowers the pH of milk which makes it acidic. In this lab we will be isolating bacterial strain in yogurt samples in petri dishes, and then apply the bacteria to milk to examine if the milk will transform into yogurt.