The chemical structure of DNA in everyone is the same. The only difference is the order of the base pairs. Like in fingerprinting, there are so many millions of base pairs in everyone’s DNA that every person has a unique sequence.

Every person could be identified using the sequence of their base pairs. However, there are so many base pairs in every person that this would be very time consuming. Repeating patterns in DNA allow scientists to use a much shorter method.

These patterns help to determine if two DNA samples can from the same person, related people or non-related people. The sequences analyzed by the scientists are patterns that are known to vary greatly among individuals. This allows the scientist to assign a probability to a match. Since 1987, more than 150 cases have been decided with the assistance of DNA fingerprint evidence.

            DNA base pair pattern identification has many uses. DNA patterns are inherited from parents, and can therefore be used to indicate paternity and maternity. They can be to confirm legal nationality and determine biological parenthood.

            DNA analysis can be used to determine whether or not a suspect was at a crime scene. DNA can be found in blood, hair, skin cells, semen or other genetic evidence left at a crime scene. It can also be used to determine the identity of a victim.

            DNA fingerprinting is an important advance in the diagnosis of inherited disorders because early detection of these disorders allows the parents and medical staff to prepare for proper treatment of a child. This research can be extended into developing cures for inherited disorders.

            DNA fingerprinting is a laboratory procedure that can be done in six steps. DNA must be recovered from the cells or tissues of the body. Restriction enzymes are used to cut the DNA at specific locations according to the DNA sequence at that location. The DNA pieces are sorted according to size through a process called electrophoresis in which the particles are passed through seaweed agarose to determine particle sizes. The DNA is transferred to nylon by placing the sheet on the gel and letting them soak. Radioactive or colored probes are added to the nylon sheet and a pattern is produced. This pattern is called a DNA fingerprint and is formed because each of the colored probes sticks in specific places on the nylon sheet. A final DNA fingerprint is made through the use of several probes at the same time to form a code.

            There are some problems with DNA fingerprinting. The repeating patterns can only present a probability of the DNA match retrieved. The probability might be 1 in 20 billion, so it is a reasonable match, but unlike a fingerprint, repeating DNA patterns are not completely unique to each person. A probability might also be 1 in 20, and this would leave a lot of doubt. The probability values assigned help to determine the chance that the DNA fingerprint belongs to the person in question.

            There is also room for error in the probing techniques used to acquire the DNA pattern. This presents a problem for court cases because it could give false results.

            DNA fingerprinting is useful because DNA structure can not be altered. Unlike fingerprints, there is no way to change the DNA fingerprint. It cannot be altered by any known treatment. It is the same for every cell, tissue and organ in a person. DNA fingerprinting is also a way of giving a quantitative assessment to an identification match. This allows for a better idea of the reliability of the results.