Starting out with Mr. Jimmy Sweet and his obsessively cleanliness, noticed something was disturbed in his room. He noticed his NOVA lollipop had been broken into and now was "worthless". Someone had broken into his room and tasted his never-opened lollipop. He has seven suspects; his sisters, Candy, Cookie, Sugar, Lolly, Honey, Brandee, and Carmela..quite the names right?? Well anyways, they have been spotted and are now in Jimmy's custody, as he begins his finger printing for DNA!
The Process
To start the process of finding his culprit, I poured restriction enzymes into the DNA. The restriction enzymes are kind of like scissors, snipping the long DNA molecules at different locations. Wherever those cuts occur depend on the code that goes along with the DNA molecule and the code within the enzymes. Our next step was pouring agarose gel into a tray on the lab counter. The agarose gel is thick and resembles Jello. It represents a molecular strainer, allowing tiny pieces of DNA to navigate through more easily than large pieces. Then, we poured the DNA into the tray with the agarose gel. It made a hole in the gel and all of the DNA pieces lay in that hole. After that we had to flip the switch on the tray with the DNA and agarose gel. This began electrophoresis, which is the process of moving molecules with an electric current. The DNA pieces have a small negative charge, so they move towards the positive end of the tray. However the gel acts like a strainer. Smaller DNA fragments move through the gel easier and farther toward the opposite end of the tray than the bigger ones. When electrophoresis is finished, the little pieces are distributed in the gel according to their lengths. After electrophoresis we placed a nylon membrane on top of the gel. Due to the difficulties of the agarose gel, DNA is transferred to a nylon membrane, which looks like a sheet of paper. The DNA got sucked up into the membrane as liquid traveled up from the gel towards an absorbent material that had been placed over the membrane. I then added probes to the membrane in the tray. The probes are bits of DNA that have been labeled radioactively. These little guys attach themselves to the DNA pieces on the nylon membrane. However they only attach where their code came upon a sequence of code with the many fragments. All of the extra probey stuff that didn't attach itself to DNA gets washed away. The next step is to put a X-ray film on top of the nylon. The radioactivity that comes from the probes, which are only at a minute number of locations on the membrane, shows connecting areas on the X-ray film. After the probes show up on the X-ray you place the film into the developer. After it is developed the X-ray film shows locations on the nylon membrane where the probes got attached to the DNA pieces, finally giving us the fingerprint! :)
Now on to the matching game! Out of his seven sisters, he has to find the one that took his one of a kind NOVA lollipop! After carefully looking and deliberating, we figured out that Honey Sweet was the criminal! Jimmy decided that Honey has to be denied dessert which is Macadamia Rum Baked Alaska-yuck!
After finding out this information, we have learned that DNA fingerprinting, can be a typically easy process, if you know what you're doing anyways; and surprisingly enough i do :)
Source 1:
http://www.pbs.org/wgbh/nova/sheppard/labwave.html
Wrongfully Convicted
DNA has helped us in many different ways from matching parents, all the way to helping solve criminal cases. In Ronald Cotton's case, he was wrongfully convicted for rapes on August 1, 1984. In January 1985, he was convicted by a jury of one count of rape and also a count of burglary. He was sentenced to life plus 54 years. Although Cotton's alibi was supported by family members, the jury wasn't allowed to hear evidence that the second victim had failed to pick Cotton out of either a police lineup or a compilation of pictures. The conviction was based on many reasons like a photo id being made by one of the victims, a police lineup id was also made by a victim. A flashlight in Cotton's home was also resembled the one used by the burglar. The rubber of Cotton's shoe was also used due to it's match with rubber found at one of the crime scenes. After all of the drama, Ronald Cotton's attorney filed an appeal. The North Carolina Supreme Court flipped the conviction because the second victim had chosen a different man from the lineup and the trial court didn't allow for this to be told to the jury. In November of 1987, he was retried, for both rapes. The second victim decided that Cotton was the assailant. Before the second trial, a man in prison, who had been convicted of almost identical assaults, told another inmate that he had committed what Ronald Cotton did. The judge refused to let the jury hear this also and Cotton was sentenced to life for both rapes. Finally after many years DNA was used to help prove Cotton's innocence. The samples from on victim or too old to be used, but the other victim's DNA swabs were given to PCR test and showed NO match to Cotton. With a request from the defense attorney, the results were then sent to the State Bureau of Investigation's DNA data base containing the DNA patterns of convicted, dangerous felons that were being held in North Carolina prisons. The state's data base brought up a match with the convict who had recently confessed to committing the crime. After Ronald's attorneys received DNA test results in May of 1995, they got ahold of the district attorney, who joined the defense attorneys in order to dismiss the charges. Finally on June 30, 1995, Cotton was finally cleared of all charges and released from prison. In July 1995, Cotton was eligible for $5,000 compensation from the state of North Carolina after he had served 10.5 years of a wrongful conviction.
Source 2:
http://www.pbs.org/wgbh/pages/frontline/shows/dna/cotton/summary.html
