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DNA Fingerprinting: Definition, Method and Application

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What is DNA fingerprinting? DNA fingerprinting is a laboratory technique that is used to determine the identity of a person using a unique pattern in the minisatellites of the genome of an individual. It was first invented in 1984 by Sir Akec Jeffreys after he realized that we can detect variations in human DNA based on these minisatellites. On average, about 99.9% of DNA between two individuals is the same, the remaining 0.1 % makes the person unique. DNA profiling, DNA testing, DNA examination, Genetic profiling, and Genetic fingerprinting are branches of DNA fingerprinting. Following is the complete process of DNA fingerprinting: RFLP (Restriction Fragment Length Polymorphism) The first step of DNA fingerprinting is to extract DNA from the biological fluid of human-like blood, buccal swabs, etc. Then molecular scissors, also called restriction enzymes are used to cut the DNA into thousand pieces of different lengths. These pieces of DNA are now separated using gel electrophoresis
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History of Fingerprint Science

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Prof. Jan Evangelista Purkinje The history of fingerprint science dates back three 3000 years as it was first used in Chinato to sign legal documents. Then, In 1823 Prof. Jan Evangelista Purkinje published a thesis describing the friction ridge patterns and classifying fingerprints into Nine categories. Sir William Herschel In 1858, An English civil servant Sir William Herschel posted in Bengal, India, started the practice of recording handprints of native Indians to sign the contract. This, greatly prevented the cheating and impersonation among native Indians to sign the contract. But, William Herschel did not publish any of his findings. Dr. Henry Fauld In 1874, Dr. Henry Fauld , a Scottish physician working in a hospital in Tokyo, Japan, published his theory on the potential use of fingerprints for personal identification. In 1880, Dr. Fauld suggested that skin ridge patterns can be proved important for the identification of criminals. He also published his findings in Book &#
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Steps involved in Agarose Gel Electrophoresis

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Agarose Gel Electrophoresis Agarose gel electrophoresis helps in the separation of DNA fragments based on their speed of movement in Agarose gel towards the anode. In this technique, the DNA sample is poured into the wells on the Agarose gel which are made using a comb. Also, a fluorescent dye called Ethidium is added to the sample DNA prior to electrophoresis to increase the viscosity of the sample which will prevent it from floating out of the wells. The migration of the sample can be seen through the gel. A DNA marker (Also called DNA ladder) is also loaded into the first well of the gel. The fragments in the markers are of known length which will be compared with the size of DNA fragments of sample DNA. Now the electric current is turned on so that the negatively charged DNA molecules move toward the positively charged anode. The shorter lengths of DNA will move faster than the longer lengths of DNA in the gel. The electric current is kept on till DNA fragments move far enoug
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Types of Fingerprint Patterns

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What are Different Types of  Fingerprint Patterns? 1. Arches Arches are found in approx 5% of the recorded fingerprints. In an Arch pattern, ridges enter from one side travel to the other side, and lift slightly at the center of the pattern (like a wave) finally exiting from the opposite side.  Based on the nature of Arches they are further divided into two types i.e. Plain Arch and Tented Arch. (a) Plain Arches Plain Arch is the simplest pattern among all fingerprint patterns. In a plain arch, the ridges enter from a side (say left) and flow to the opposite side (Right) by making a small rise at the center like a wave. They don't have any core deltas but they do have numerous ridge formations like ridge endings, bifurcations, dots, and islands. (b) Tented Arches In this type of Arch, most of the ridges enter from one side and flow towards the opposite side by making a definitive angle ( 90 degrees or less ) or standing straight at the center of the pattern and finally exiting fro
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Classification of Thermal Injuries

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A) Cold Injuries 1. General Effects 1. Hypothermia Exposure of the body to cold, below temperature 35 ℃ (95 ℉) is called Hypothermia. When the temperature of the body falls below 32 ℃  to 24 ℃ , there is disorientation, loss of consciousness, loss of reflex, and a fall in respiration heart rate, and blood pressure. Red patches and pallor of the skin, edema of the face, and stiffness of neck muscle may be seen. Postmortem Findings 1. External Patches of pink/brownish-pink discoloration on the skin. Edema on feet and blistering of skin can be seen. The extremities may be white (White deaths) 2. Internal Lungs are congested and show hemorrhages. The heart shows dilation of the right atrium and ventricle. Wischnewslay spots may be seen in the stomach. Fatty changes in the liver and contracted spleen. Hemorrhages in core muscle. Ulceration of the colon. 2. Local Effects 1. Chilblain These are red, itching, and skin lesions due to exposure to cold. They may be associated with edema and blis
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Presumptive and Confirmatory Tests for Blood

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(a) Presumptive Test 1. Phenolpthalein Test (Kastle Meyer Test) Place a small portion of the suspected bloodstain, such as a cutting, swab, or extract, onto a piece of filter paper. Two or three drops of ethanol are added to the stain. Add two drops of the prepared phenolphthalein solution to the stain. After ensuring that no color develops during this waiting period, 2-3 drops of 3% hydrogen peroxide are introduced to the stain. The emergence of a vibrant pink color signifies a positive result for peroxide activity, indicating the presence of hemoglobin. 2. Leuomalachite Green Test (LMG) A small curring, swab, or extract of the suspected bloodstream is placed on filter paper. Add leucomalachite green solution to the stain. If indicate green color appears then it gives a positive test for the presence of blood. 3. Alder Test (Benzidine Test) It is the oldest method for the detection of blood which was developed by Alder in 1904. It produces dark blue color in the reaction of blood
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Diagnosis and Management of Poisoning Cases

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Diagnosis of Poisoning Cases  1. Diagnosis of poisoning in living Following are the symptoms that suggest the poisoning in living: The sudden onset of symptoms such as abdominal pain, nausea, vomiting, diarrhea, and collapse. The sudden occurrence of coma accompanied by pupil constriction. Unexplained coma, especially in children. An adult with a known history of depressive illness experiencing a state of coma. Rapid onset of neurological or GIT illness. Sudden onset of convulsion. Delirium with dilated pupils. Paralysis, Jaundice, and hepato-cellular failure. 2. Diagnosis of poisoning in the dead (Postmortem Examination) Internal Findings 1. Smell To detect unusual odors in the brain, the first step is to open the skull. 2. Mouth and throat Thoroughly examine for indications of inflammation, erosion, or staining. Necrosis of the pharynx will be seen in case of death caused by sulphonamide and barbiturates. 3. Respiratory System Corrosive poisons show edema and congestion of the mu
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Quality Management: Definition, Principle and Stages

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What is Quality Management? Quality management is a process to make sure that a product or service made by the company meets the standard of excellence and satisfies the customer's needs. Quality management not only focuses on product quality but also tells us the ways of achieving it.  Components of Quality Management There are four main components of quality management: 1. Quality Control (QC) It is a process in which the quality is maintained and reviewed considering all factors involved in the production.' 2. Quality Assurance (QA) It is a process of preventing mistakes and manufacturing defects in a product and assuring the customer that the product delivered to him will be of high quality. 3. Quality Improvement (QI) It is a process of continuous improvement in the quality of products through time-to-time inspections, checks, and reviews. This helps to evolve the product and meet the customer's expectations. 4 Quality Planning (QP) It is the process of identifying t
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Types of Ballistics in Forensic Science

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What is Ballistics? Ballistics is a branch of science that deals with the propulsion, flight, and impact of projectiles on the target. The term "Ballistics" finds its roots in the Greek word "Ballein," signifying "to throw" or "to project." It is Colonel Godard who first coined forensic ballistics. He used the systematic study of firearms and ammunition for investigation and justice. Types of Ballistics Ballistics is divided into three major types: 1. Internal Ballistics Internal Ballistics is the branch of ballistics that deals with the study of the projectile inside the barrel of the firearm that is from when the firing pin hits the primer to the time the bullet exists the barrel from the muzzle end of the firearm. It is also known as Initial or Interior Ballistics. Internal ballistics helps in linking the projectile with the firearm by studying scratch marks on the projectile, velocity of the projectile, defects in the barrel, Erratic
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Total Quality Management: Definition, Phases and Principles

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What is Total Quality Management? Total Quality Management (TQM) is a process of continuous effort by the management as well as employees of the company to improve processes, products, and services for customer satisfaction.  By fostering a collective commitment among employees to enhance work culture, processes, services, systems, and more, it paves the way for sustained success in the long run. Phases of  Total Quality Management (TQM) Total Quality Management (TQM) is divided into four phases that are Plan, Do, Check, and Act. It is also called PDCA Cycle. 1. Planning Phase It is the first and most crucial phase in Total Quality Management (TQM). In this phase, employees come up with their problems and queries which need to be addressed. A proper plan or road map is prepared to find the solution to all the queries and problems. 2. Doing Phase In this phase, employees develop a detailed solution to the problems that they identified in the Planning Phase. Different strategies are
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