Touch DNA
Summery
The touch DNA method was discovered in the past five years. The method acquired the name “touch DNA,” because of the fact that it examines skin cells left behind on various objects, weapons, and victims the assailants touched at the crime scene.The method of touch DNA has drastically improved the number of items of evidence that can be used in DNA detection. In the 1980s, to be able to perform a DNA analysis, forensic investigators had to have a blood or semen stain approximately the size of a quarter. In the 1990s the size of the sample needed dropped to about the size of a dime; after that they just needed a sample big enough to see, “if you can see it, you can analysis it.” With the touch DNA method you don’t have to be able to see the sample; it only requires seven or eight cells from the outermost layer of skin.
Here is how the DNA touch method works:
1) First, investigators recover cells from the crime scene by swabbing objects, victims, articles of
clothing, and other things that were or may have been touched by the assailants.
2) Next, a process called polymerase chain reaction, or PCR, is used to generate several copies of
the genes.
3) Then scientists add in fluorescent compounds which then attach themselves to thirteen
specific locations on the DNA resulting in a very specific genetic portrait of that person.
The entirety of the process takes a few days.
The thirteen specific locations, to which the copied genes that are mixed with the fluorescent compounds, were intentionally chosen because they vary greatly from person to person and to not give away specific information like race, genetic diseases, gender, or personal health. The reason behind this being: authorities don’t want individuals’ personal health information to be used for law-enforcement purposes, like interrogations. The chances of two people having the same DNA profiles are extremely small.
My Response: I think it’s very beneficial that the touch DNA method only requires seven or eight skin cells as opposed to the methods in the 1980s and 1990, which required a sample of blood or semen the size of a quarter and later a dime. In some cases blood or semen may not be present at the scene of the crime. God made each of us differently; we all have our different DNA’s for example and this can be used to help fight crime. It’s just neat to see another reason/aspect as to why God made us all unique and different; clearly this is not the only reason why God gave us all our own DNA, but it is just gives us a little more insight to the human body and why God designed it the way he did.
http://www.sciam.com/article.cfm?id=experts-touch-dna-jonbenet-ramsey
Hannah Eastwood
posted by Hannah @ 5:24 PM
3 Comments:
I always watch things like that on TV, but it never really hit me how amazing it can truly be. How they only need a few cells to get a DNA sample and track down the suspect. The advancements have really helped the whole process also , really making it easier to match the DNA to the correct person.
This seems to be very useful because in every crime you are not going to be able to find blood or semen. Even if a crimal thought they were being careful and wore gloves, a simple graze or the arm or even cheek could give them away without the criminal even realizing it. On the other hand, a figerprint would be far less noticable than a drop of blood, so I think investigators would have to search harder. It is hard for me to grasp that with seven cells, invisible to the naked eye, someone could identify me. It is remarkable that of the billions of people in the world, not one person has my same fingerprint.
I think it's really amazing how you don't even need to see the sample to analyze it. This shows how far our science and technology has come in the past thirty years. And this will be able to help in crimes to match the DNA to the right person.
Post a Comment
<< Home