DNA Fingerprinting - Class XII

• DNA fingerprinting  is the process of determining an individual's DNA characteristics, which are as unique as fingerprints. 
• The first patent covering the modern process of DNA fingerprinting was filed by Dr. Alec Jeffrey Glassberg in 1983.
• DNA fingerprinting  is a forensic technique in criminal investigations, comparing criminal suspect's profiles to DNA evidence so as to assess the likelihood of their involvement in the crime.

DNA fingerprinting is a forensic technique which identify the individuals by their DNA characteristics. A variable number tandem repeat (or VNTR) refers to presence of a short nucleotide sequence as a tandem repeat on many chromosomes; it exhibit variations in length and number of repeats between individuals. VNTR are 10-100 bp long. This DNA polymorphism is revealed during DNA finger printing in creating DNA profile of individuals. It was invented by AIec Jeffery. The first step in DNA finger printing is extraction of useable DNA followed by its digestion with restriction enzymes to produce the restriction fragments length polymorphisms, or RFLPs. The fragments are sorted according to size by gel electrophoresis. The DNA fragments are then transferred from the gel to the surface of the nylon via southern blotting. For the purpose, the agarose gel is mounted on filter-paper wick and the hybridization membrane is sandwiched between the gel and any absorbent material, which draw the transfer buffer through the gel by capillary action. The buffer flow draw the DNA molecules which are then immobilized on the synthetic membrane. Finally, radioactive probes are washed over the nylon surface to allow their joining to any DNA fragments of same composition.  A photographic film on top of the nylon surface to make a genetic fingerprint. 

DNA finger printing is a forensic technique which identifies the individuals by their DNA characteristics. A variable number tandem repeat (or VNTR) refers to the presence of a short nucleotide sequence as a tandem repeat on many chromosomes; it exhibits variations in length and number of repeats between individuals. VNTR are 10-100 bp long. This DNA polymorphism is revealed during DNA finger printing in creating DNA profile of individuals.  It was invented by AIec Jeffreys. The first step in DNA finger printing is the extraction of usable DNA followed by its digestion with restriction enzymes to produce the restriction fragments length polymorphisms or RFLPs. The fragments are then sorted according to size by gel electrophoresis. The sorted DNA fragments are then transferred from the gel to the surface of the nylon via southern blotting. For the purpose, the agarose gel is mounted on filter paper wick and the hybridization membrane is sandwiched between the gel and any absorbent material, which draw the transfer buffer through the gel by capillary action. The buffer flow draws the DNA molecules which are then immobilized on the synthetic membrane. Finally, radioactive probes are washed over the nylon surface to allow their joining to any DNA fragments of same composition. A photographic film on top of the nylon surface to make a genetic fingerprint. 

DNA fingerprinting is a test which is used to identify and evaluate the genetic information called as DNA in a person's cells. It is called as a "fingerprint" because it is very unlikely that any two people would have exactly the same DNA information, in the same way that it is very unlikely that any two people would have exactly the same physical fingerprint. The test is used to determine whether a family relationship exists between two people, to identify organisms causing a disease and to solve crimes. 

Alec Jeffreys is the scientist credited with developing the technique of DNA fingerprinting in 1984.

The Centre for DNA Fingerprinting and Diagnostics (CDFD) is an autonomous organization located in Hyderabad, India.

DNA profiling or fingerprinting is used in, parentage testing and criminal investigation, to identify a person or to place a person at a crime scene, techniques which are now employed globally in forensic science to facilitate police detective work and help clarify paternity and immigration disputes. Therefore, the correct answer is option A.

Forensic science is the application of science to the law. In criminal cases, forensic scientists are often involved in the search for an examination of physical traces which might be useful for establishing or excluding an association between someone suspected of committing a crime and the scene of the crime or victim. 

DNA fingerprinting is a method used to identify an individual from a sample of DNA by looking at unique patterns in their DNA. DNA is present in blood, hair, semen and various other body cells which can be used to isolate DNA for the process of DNA fingerprinting.

Kary Mullis invented the Polymerase Chain Reaction (PCR) technique in 1983, for which he later received the Nobel Prize.

About 3% or so of the human genome has highly repetitive sequences termed as simple-sequence DNA or satellite DNA that are repeated in multiples per cell and generate tandem repeats. This DNA polymorphism is revealed during DNA finger printing in the identification of paternity since it is very remote possibility to have two individuals same repeats of satellite DNA throughout the genome except they share a biological relationship. This is because a child gets half DNA from father and half from the mother. Restriction enzymes of genome produce the restriction fragments length polymorphisms, or RFLPs depending on the location of restriction sites which are then sorted by gel electrophoresis followed by southern blotting. The blots of parental and child genome are compared for sequence homology using radioactive probes; option D is correct. 

DNA fingerprinting is a versatile technique used for identifying individuals, determining biological relationships, and analyzing genetic polymorphism in forensic and medical contexts.

DNA fingerprint is the unique DNA pattern of each individual. It is the same for every cell, tissue and organ of an individual. DNA fingerprinting is a method used to identify an individual on the basis of unique patterns of its DNA. It is used in the diagnosis of inherited disorders like cystic fibrosis, Alzheimer's disease, Huntington's disease, Sickle cell anemia.

A minisatellite is a tract of repetitive DNA in which certain DNA motifs (ranging in length from 10–60 base pairs) are typically repeated 5-50 times. ... Minisatellites and their shorter cousins, the microsatellites, together are classified as VNTR (variable number of tandem repeats) DNA.

Polymerase chain reaction (PCR) is an amplification technique for cloning the specific or targeted parts of a DNA sequence to generate thousands to millions of copies of DNA of interest. This molecular “xeroxing” process involves heating and cooling samples in a precise thermal cycling pattern over ≈30 cycles. PCR uses a small amount of template DNA, two primers that flank the target sequence, nucleotides, and thermostable DNA polymerase to amplify a specific region of DNA.

Gene amplification can occur in situ, forming a so-called homogeneously staining region (HSR) in the normal chromosomal location of the gene (many copies of the gene are present as tandem repeats) or as so-called double minute chromosomes (extra chromosomal fragments of DNA containing multiple copies of the amplified gene). Gene amplification can also occur as an artifact when tumor cells are cultured in vitro.

Microsatellites are polymorphic repeating units of 1–6 base pairs in length, found in human DNA. Microsatellites can be amplified for identification by PCR and can be used as molecular markers. Microsatellite analysis (MSA) is a PCR analysis of DNA in exfoliated urine cells.

Discovering their high level of variability, Sir Alec Jeffreys developed DNA fingerprinting based on minisatellites, solving the first immigration case by DNA in 1985, and the first forensic murder case, the Enderby murders in the United Kingdom, in 1986.

Satellite DNA consists of arrays of tandemly repeating sequences that are widely present (>30%) in the genome. Satellite DNA is mainly present in heterochromatin or the tightly packed regions of chromosomes in centromeres, telomeres, and sometimes even in the euchromatin region (active region of the genome).

Satellite DNA consists of arrays of tandemly repeating sequences that are widely present (>30%) in the genome. Satellite DNA is mainly present in heterochromatin or the tightly packed regions of chromosomes in centromeres, telomeres, and sometimes even in the euchromatin region (active region of the genome).

Southern blotting is the technique used to transfer DNA fragments from a gel to a membrane for hybridization, which is a core step in DNA fingerprinting.

VNTR stands for Variable Number of Tandem Repeats, which are short DNA sequences repeated in tandem and vary in number between individuals.

DNA can be extracted from any nucleated cell. White blood cells, hair roots, and various body secretions (like semen or saliva) all contain sufficient DNA for fingerprinting.

DNA fingerprinting primarily relies on the analysis of minisatellite DNA, which consists of highly polymorphic VNTR sequences.

DNA probes used in fingerprinting are single-stranded DNA segments labeled with radioactive isotopes (or fluorescent markers) to detect complementary sequences on the membrane.

DNA fingerprinting is widely used in forensics, paternity testing, and the study of genetic polymorphism, making 'all the above' the correct choice.

The basis of DNA fingerprinting is the high degree of polymorphism in satellite DNA (specifically minisatellites/VNTRs) among individuals.

Mature human erythrocytes (red blood cells) lack a nucleus and therefore do not contain genomic DNA, making them unsuitable for DNA fingerprinting.

DNA fingerprinting relies on detecting variations in specific repetitive DNA regions. Variable Number of Tandem Repeats (VNTRs) are highly polymorphic sequences used as markers for individual identification.

Polymerase Chain Reaction (PCR) is the standard laboratory technique used to amplify small segments of DNA, making them sufficient for analysis in fingerprinting.

DNA ligase is the enzyme responsible for joining DNA fragments together by forming phosphodiester bonds. It is essential in molecular cloning and DNA repair.

DNA fingerprinting is a powerful forensic tool used to establish biological relationships, including paternity and maternity, as well as identifying individuals in criminal investigations.

Probes used in DNA fingerprinting are known, single-stranded DNA sequences that are radioactively or fluorescently labeled to bind specifically to complementary target sequences on the membrane.

The correct sequence is: Isolation of DNA (II), Digestion by restriction enzymes (VI), Separation by electrophoresis (V), Transfer/blotting (III), Hybridization (I), and Detection by autoradiography (IV).

Repeated DNA sequences can act as more or less discrete elements in the genome. They can vary in the number of copies of repeat units from one chromosome to the next (polymorphism). The repeat copy number can expand through a unique form of mutation process referred to as ‘dynamic mutation.’ They are useful in the formation of pseudogenes and also in making multiple copies of a product.

DNA fingerprinting identifies individuals based on repetitive DNA sequences, specifically minisatellites (a type of satellite DNA) which exhibit high levels of polymorphism.

Two samples of DNA are required, one from the site of crime while another from the suspected criminal. These both samples of DNA are matched by DNA fingerprinting which involves identifying patterns of DNA known as a variable number of tandem repeats. PCR amplification is used to amplify DNA segments and restriction enzymes for cutting of DNA segments. Gel electrophoresis is used to separate these cut DNA segments based on their size.