HOW DNA FINGERPRINTING WORKS
DNA fingerprinting is a widespread method to distinguish between human beings at a genetic level. The test itself is widely used for determining blood relationships between two people, tracing diseases, and aiding in criminal investigations. A fingerprint, unlike common belief, is not used to obtain the individuals DNA.
There are two types of fingerprints. The two types of fingerprints are conventional fingerprints and DNA fingerprints. Conventional fingerprints are on the fingertips, and can be altered by surgery. Each finger has a different fingerprint that cannot distinguish an individual genetically. DNA fingerprints are like a copy of a person's DNA structure. It is the same for every cell in their body, and it greatly useful. A DNA fingerprint can be collected from various places. Small samples of cells are needed for the test, and they are often obtained through a drop of blood. In unusual or necessary circumstances, the root of a hair, skin scrapings, or mouth swabs may be used, as they can all provide the same result.
There are two types of fingerprints. The two types of fingerprints are conventional fingerprints and DNA fingerprints. Conventional fingerprints are on the fingertips, and can be altered by surgery. Each finger has a different fingerprint that cannot distinguish an individual genetically. DNA fingerprints are like a copy of a person's DNA structure. It is the same for every cell in their body, and it greatly useful. A DNA fingerprint can be collected from various places. Small samples of cells are needed for the test, and they are often obtained through a drop of blood. In unusual or necessary circumstances, the root of a hair, skin scrapings, or mouth swabs may be used, as they can all provide the same result.
Steps in the DNA fingerprinting process
1. The cell sample is taken from the individual
commonly a doctor collects a small amount of blood in the upper arm of the patient through a needle.
2. DNA is extracted from the cell sample.
3. The DNA is split into fragments by a restrictive enzyme, and then separated into bands by gel electrophoresis
the restrictive enzyme splits the DNA at a specific sequence that produces fragments of different lengths. These fragments are called RFLP's (restriction fragment length polymorphisms). During the process of gel electrophoresis, the fragments are distinguished by their sizes and placed in order accordingly. This forms a line of DNA fragments.
4. The DNA fragments are transferred to a nylon membrane
1. The cell sample is taken from the individual
commonly a doctor collects a small amount of blood in the upper arm of the patient through a needle.
2. DNA is extracted from the cell sample.
3. The DNA is split into fragments by a restrictive enzyme, and then separated into bands by gel electrophoresis
the restrictive enzyme splits the DNA at a specific sequence that produces fragments of different lengths. These fragments are called RFLP's (restriction fragment length polymorphisms). During the process of gel electrophoresis, the fragments are distinguished by their sizes and placed in order accordingly. This forms a line of DNA fragments.
4. The DNA fragments are transferred to a nylon membrane
(More Information on the procedure of DNA Fingerprinting: CLICK HERE)
ADDITIONAL RESOURCES:
MCGRAW HILL ANIMATION ON DNA FINGERPRINTING: HTTP://HIGHERED.MCGRAW-HILL.COM/SITES/DL/FREE/0072835125/126997/ANIMATION40.HTML