How DNA Evidence Works

"CSI: Crime Scene Investigation" of the CBS TV series attracts more than 20 million viewers per episode and is the most successful in the television industry. The popularity of the show is attributed to writers and actors who turn the story into reality. But another interesting element is that the Las Vegas Crime Research Institute is trying to solve the state-of-the-art technology used in crime. In laboratory forensic kits, DNA evidence collection and analysis is the first choice. Also, because it is widely used in programs such as "CSI" and "cold case", many juries in the real world court are paying attention. To present DNA evidence - - whether an incident is necessary

It is hard to believe that the evidence of DNA is so fast. Since 1985, a technique to identify suspects using his or her own genetic blueprint has appeared. Back then, Alec Jeffreys and his colleagues in the UK demonstrated the use of DNA in criminal investigation for the first time. Since then, DNA evidence has played an increasingly important role in the criminal justice system of many countries. It has been used to prove that a suspect is involved in a crime and releases someone accidentally convicted. In addition, in the United States, it is part of some famous criminal cases.

At the center of DNA evidence is the biomolecule itself. It serves as a usage and blueprint for all substances in the body (see Cell How It Works for details). A DNA molecule is a long twisted chain called a double helix. DNA seems very complicated, but it actually consists of 4 nucleotides.

These nucleotides exist as base pairs and are connected to each other in a staircase form of a ladder. Adenine and thymine are always paired together and cytosine and guanine are bound. Most DNA does not differ from person to person, but about 3 million base pair DNA (about 0.10% of the whole genome) varies from person to person.

In human cells, DNA is packed tightly on 23 pairs of chromosomes. One member of each chromosome pair comes from your mother and the other member comes from your father. In other words, your DNA is a combination of your mother and your father's DNA. Unless you have the same twin, your DNA is unique.

That's why DNA evidence is very useful in research - it is nearly impossible for others to have the same DNA as you. However, as this article shows, using DNA evidence to capture offenders is not as easy as 'CSI'. The first step in investigating DNA evidence is the crime scene and biometric evidence gathered by detectives.

Physical evidence is any tangible thing that connects a criminal with a crime scene. Biological evidence including DNA is physical evidence. However, biological evidence is invisible to the naked eye. DNA testing extends the scope of useful biological evidence. DNA testing can be performed against all the biological evidence found at the crime scene. Samples such as feces and vomit can be inspected, but the laboratory can not be routinely inspected. Since only a few cells are enough to get DNA information to help you with your case, the next list will include some general evidence that you may need to gather, possible locations and evidence of DNA List the sources of. Remember that because cell staining can not be seen, there is not enough cells for DNA typing.

At the center of DNA evidence is the biomolecule itself. It serves as a usage and blueprint for all substances in the body (see Cell How It Works for details). A DNA molecule is a long twisted chain called a double helix. DNA seems to be very complicated, but it actually consists of only 4 nucleotides. These nucleotides exist as base pairs and are connected like a ladder in the ladder. Adenine and thymine are always paired together and cytosine and guanine are bound. Most DNA does not differ from person to person, but about 3 million base pair DNA (about 0.10% of the whole genome) varies from person to person.