DNA Fingerprinting

Introduction 

Fingerprints are unique to persons and so is the DNA. In fingerprinting we get loop, whorl and arch which can be defined as follows-

• Loop: This pattern of fingerprint classification involves 60–65% of all fingerprints
• Whorl: This pattern of fingerprint classification involves 30–35% of all fingerprints
• Arch: This pattern of fingerprint classification involves 5% of all fingerprints
• The complex classification of fingerprint patterns is further broken down into plain or tented arches. Loop patterns can be either radial or ulnar. The pink part of the finger is the starting point of the ulnar loops, and the lower arm bone constitutes the ulna. The thumb side of the finger is the starting point of the radial loops. The whorl patterns are further classified into plain whorls, double loop whorls, composite whorls, peacock eye whorls, accidental whorls, and central pocket loop whorls. 

Just like the fingerprints are used to find out criminals in the same way  DNA fingerprinting is a modern technique which is used to identify the persons of interest. This technique is more accurate and is used to solve various issues related to paternity,etc. 

DNA Fingerprinting

DNA fingerprinting is a practice that instantaneously senses numerous DNA segments at the end of chromosomes that have repeated sequences in the genome to reveal a unique pattern for an individual. That is called a DNA fingerprint. The probability of any two individuals having a similar DNA fingerprint is minimal unless they are identical twins. 

DNA Fingerprinting Definition

DNA fingerprinting is a laboratory practice that facilitates establishing a link between the evidence and the suspect. The evidence is biological, the suspect is the accused in the criminal investigation, and the DNA fingerprinting chemical test reveals the genetic makeover of the individual. 

Fingerprint Test

The cell samples of a person are taken for a DNA fingerprinting test. The samples can be of any kind. They can range from swabs taken from inside the mouth, cells from the skin, or cells from the root of the hair. They can also be from saliva, sweat, or any other body fluid. 

Taking cell samples from blood is the easiest way to perform the DNA fingerprinting test. Chemicals are then used to separate the DNA from the blood, and it is then dissolved in water to reveal the results of the DNA fingerprinting test. 

Another chemical process is involved in cutting the DNA into several smaller segments. A minimum of 5-10 base pairs are formed to make the DNA samples longer. 

The DNA samples are mixed with gel, and then run through an electrical current to separate the smaller and larger DNA strips. The test results are more accurate when the shorter DNA segments are tested. 

Uses of DNA Fingerprinting

DNA fingerprinting has many purposes. They are as follows:

• It is used in the court of law for cases and resolving legal issues
• It can be the evidence of being connected to a person
• A person who may be a suspect in a case can be identified through it
• The test can be used to identify parents, siblings, or relatives
• An old and damaged dead body or a body beyond a recognizable state can be identified through it
• DNA fingerprints are accurate, and the police of most countries store DNA records as a part of their files
• DNA fingerprinting also carries medical uses. When an individual requires an organ to be replaced, the tissue from the donor’s organ is matched with the tissues of the person who needs an organ transplant
• Hereditary diseases can be identified through the test, and the corresponding treatment, remedies, or precautions can be taken

Process of DNA Fingerprinting

The process of DNA fingerprinting involves a few significant steps, such as collecting the DNA samples, extracting the DNA, amplification, and analysis of the results. The following are the details of the steps taken:

Step 1: Collection of the DNA samples: DNA samples are collected from body fluids such as blood or saliva; or from the skin, hair roots, or other tissues.

Step 2: Extraction of the DNA: A good quantity and the suitable quality of DNA are obtained for better results. There are quite a few methods available for DNA extraction, including the phenol-chloroform extraction method, the CTAB DNA extraction method, and the Proteinase K extraction method. There are DNA extraction kits easily available in the market.

Step 3: Select a technique for your desired results. The PCR-based gel electrophoresis technique should be selected if the purpose of the test is to detect maternal cell contamination. If the test is being done for forensic analysis, capillary gel electrophoresis and the real-time PCR technique are sufficient to produce the results.

Step 4: Analysis of the reports: The results vary on the basis of the deployed technique. When the DNA samples of various profiles are compared, information about the similarities and dissimilarities between the individuals is obtained. DNA fingerprinting is automated in the modern world and computers are used to fetch the results. 

Conclusion 

Now that you have learned more about DNA fingerprinting, you must have a deeper understanding of what it is, its definition, its classification, the uses and importance of DNA fingerprinting tests in the real world, and more.