Uses of DNA Forensic Identification

As you have read in the previous posts that have been included in this blog, you can see that DNA Fingerprinting can be very complicated but also extremely useful. Did you know that DNA Identification was used in confirming the remains of many people that were killed in the September 11th attacks on the WTC. A Database was also created to help find the victims of the Holocaust. Creating this project was called the Shoah Project. It succeeded in reuniting many families with their loved ones. As you can see, DNA is not only used for convicting criminals or for even setting the innocent free. It is not only used for paternity tests either, but also helping many people in identifying remains of lost relatives and friends. I find DNA Forensics to be one of the most important technologies that has been discovered and evolved. With all the good it has done over the years and the progress that has been made, I look foprward to what else it has to offer in the near future and what new things develop.

How Forensic Identification Works

Any type of organism can be idfentified by examination of DNA sequences unique to that species, as I mentioned in my last post. Identifying individuals within a species is less precise at this time, although when NA sequencing technologies progress farther, direct comparison of very large DNA segments, and possibly even whole genomes, will become feasible and practible and will allow precise individual identification.

To identify individuals, forensic scientists scan 13 DNA tregions, or loci, that vary from person to person and use the data to create a DNA profile of that individual. This is sometimes called a DNA Fingerprint and is why I use the name as my title and topic. There ios an extremely small chance that another person has the same DNA profile for a particular set of 13 regions.
 
Some examples of DNA uses for Forensic Identification

1. Identify potential suspects whose DNA may match evidence left at crime scenes
2. Exonerate persons wrongly accused of crimes
3. Identify crime and catastrophe victims
4. Establish paternity and other family relationships
5. Identify endangered and protected species as an aid to wildlife officials (could be used for prosecuting poachers
6. Detect bacteria and other organisms that may pollute air, water, soil, and food
7. Match organ donors with recipients in transplant programs
8. Determine pedigree for seed or livestock breeds
9. Authenticate consumables such as caviar and wine

What is DNA Fingerprinting?

The chemical structure of everyone's DNA is the same. The only difference between people or even animals is the order of the base parts. I described a little about the base parts in the last post published in this blog. There are so many millions of base parts in eachnperson's DNA that every single person has a different sequence. Using these sequences, every person could be identified solely by the sequence of their base pairs. However, because there are so many millions of base pairs, the task would be very time-consuming. Instead. scientists are able to use a shorter method, because of repeating patterns in DNA. These patterns do not, however, give an individual "fingerprint," but they are able to determine whether two DNA samples are from the same person, related people, or non-related people. Scientists use a small number of sequences of DNA that are known to vary among individuals a great deal, and analyze those to get a certain probability of a match.

Reference: www.protist.biology.washington.edu

So, What is DNA Anyway?

As you read each post in this blog, you should get a great understanding of what the technology of DNA Fingerprinting is, along with how and why it used. Before I begin to explain this amazing technological advance to you all, I think I should start by giving a brief explanation of what “DNA” is first. D.N.A stands for Deoxyribonucleic Acid. DNA is a chemical structure that forms chromosomes. A piece of a chromosome that dictates a particular trait is called a gene. Structurally, DNA is a double helix, which means that two strands of genetic material are spiraled around each other. Each strand contains a sequence of bases which are also called nucleotides. A base is one of four chemicals (adenine, guanine, cytosine and thymine). The two strands of DNA are connected at each base. Each base will only bond with one other base, as follows: Adenine (A) will only bond with Thymine (T), and Guanine (G) will only bond with cytosine (C). So for example, if one strand looks like this---  A-A-C-T-G-A-T-A-G, then the DNA strand bound to it will look like this---  T-T-G-A-C-T-A-T-C. DNA strands are read in a particular direction, from the top (called the “5” or “five prime” end) to the bottom (called the “3” or “three prime” end). In a double helix, the strands go opposite ways. Now that you have a basic idea of what DNA is and how it is examined, the posts that will follow this one and all the information that I will provide for you should now be easier to understand. I hope you all enjoy this very interesting and informative blog on this subject as much as I do. Please feel free to leave your comments and posts as often as you want. Enjoy!!!

Background Information

Molecular Biologist Alec Jeffreys devises a way to make the analysis of more than 3 million units in the human DNA sequence much more manageable by comparing only the parts of the sequence that show the greatest variation amoung people. His method quickly finds its way into the courts, where it is used to exonerate people wrongly accused of crimes and to finger the true culprits. The year that this DNA fingerprinting development started was 1984. I truly think that this invention of technology is an extremely important one and has had nothing but good results from it. I hope you all enjoy reading and posting on this topic. Any questions or comments please feel free to post. I check back on this blog often.