DNA fingerprinting

n. the use of a DNA probe for the identification of an individual, as for the matching of genes from a forensic sample with those of a criminal suspect. Also called genetic fingerprinting. [1985–90] DNA fingerprint,
n.

DNA fingerprinting

The use of a sample of DNA to determine the identity of a person within a certain probability. DNA fingerprinting is done by analyzing repeating patterns of base pairs in DNA sequences that are known to vary greatly among individuals.

DNA fingerprinting

DNA profiling,

any of several similar techniques for analyzing and comparing DNA from separate sources, used especially in law enforcement to identify suspects from hair, blood, semen, or other biological materials found at the scene of a violent crime. It depends on the fact that no two people, save identical twins, have exactly the same DNA sequence, and that although only limited segments of a person's DNA are scrutinized in the procedure, those segments will be statistically unique.

Methods

A common procedure for DNA fingerprinting is restriction fragment length polymorphism (RFLP). In this method, DNA is extracted from a sample and cut into segments using special restriction enzymes. RFLP focuses on segments that contain sequences of repeated DNA bases, which vary widely from person to person. The segments are separated using a laboratory technique called electrophoresis, which sorts the fragments by length. The segments are radioactively tagged to produce a visual pattern known as an autoradiograph, or "DNA fingerprint," on X-ray film. A newer method known as short tandem repeats (STR) analyzes DNA segments for the number of repeats at 13 specific DNA sites. The chance of misidentification in this procedure is one in several billion. Yet another process, polymerase chain reactionpolymerase chain reaction
(PCR), laboratory process in which a particular DNA segment from a mixture of DNA chains is rapidly replicated, producing a large, readily analyzed sample of a piece of DNA; the process is sometimes called DNA amplification.
..... Click the link for more information. , is used to produce multiple copies of segments from a very limited amount of DNA (as little as 50 molecules), enabling a DNA fingerprint to be made from a single hair. Once a sufficient sample has been produced, the pattern of the alleles (see geneticsgenetics,
scientific study of the mechanism of heredity. While Gregor Mendel first presented his findings on the statistical laws governing the transmission of certain traits from generation to generation in 1856, it was not until the discovery and detailed study of the
..... Click the link for more information. ) from a limited number of genes is compared with the pattern from the reference sample. A nonmatch is conclusive, but the technique provides less certainty when a match occurs.

Applications

In criminal investigations, the DNA fingerprint of a suspect's blood or other body material is compared to that of the evidence from the crime scene to see how closely they match. The technique can also be used to establish paternity. First developed in 1984 by Alec Jeffreys, a British professor of genetics at the Univ. of Leicester, DNA fingerprinting has been accepted in most courts in the United States, and has in several notable instances been used to exonerate or free persons convicted of crimes, but the Supreme Court has ruled (2009) that convicted criminals do not have a constitutional right to DNA testing. All states have established DNA fingerprint databases and require the collection of DNA from convicted felons, and the Federal Bureau of Investigation has instituted a national DNA fingerprint database linking those of the states and including DNA collected in connection with federal offenses. DNA fingerprinting is generally regarded as a reliable forensic tool when properly done, but some scientists have called for wider sampling of human DNA to insure that the segments analyzed are indeed highly variable for all ethnic and racial groups. It is possible to create false genetic samples and use them to misdirect forensic investigators, but if those samples have been produced using gene amplification techniques they can be distinguished from normal DNA evidence.

The techniques used in DNA fingerprinting also have applications in paleontology, archaeology, various fields of biology, and medical diagnostics. It has, for example, been used to match the goatskin fragments of the Dead Sea Scrolls. In biological classificationclassification,
in biology, the systematic categorization of organisms into a coherent scheme. The original purpose of biological classification, or systematics, was to organize the vast number of known plants and animals into categories that could be named, remembered, and
..... Click the link for more information. , it can help to show evolutionary change and relationships on the molecular level, and it has the advantage of being able to be used even when only very small samples, such as tiny pieces of preserved tissue from extinct animals, are available.

Bibliography

See D. H. Kaye, The Double Helix and the Law of Evidence (2010).

DNA fingerprinting

[‚dē‚en′ā ′fiŋ·gər‚print·iŋ] (genetics) genetic fingerprinting

DNA fingerprinting

DNA fin·ger·print·ing

a technique used to compare individuals by molecular genotyping. DNA isolated from a biologic specimen is digested and fractionated. Southern hybridization with a radiolabeled repetitive DNA provides an autoradiographic pattern unique to the individual. Synonym(s): DNA profiling, DNA typing

DNA fingerprinting depends on the detection of distinctive DNA sequences in human cellular material (skin, hair, blood, semen). The principal applications of this technique, all of which are based on the premise that no two people have exactly the same genetic makeup, are in determining paternity and maternity, identifying human remains, and matching biologic material left at a crime scene with that of a suspect. The most distinctive features of a person's genome are not the genes themselves but variations in the length and distribution of nongenetic material between gene loci. Although these do not transmit genetic information, they are highly consistent within the cells of each person and highly variable from one person to another. Distinctive nucleotide sequences that are most useful in DNA fingerprinting are variable number tandem repeats (VNTRs) and short tandem repeats (STRs). In DNA fingerprinting, the specimen is split into nucleotide fragments by treatment with restriction enzymes and then subjected to gel electrophoresis so as to yield a characteristic pattern of banding. Radioactive probes, composed of short nucleotide sequences (10-15 base pairs for VNTRs, 3-4 pairs for STRs), then identify sites of tandem repeats and hybridize with them. Comparing the results from two or more DNA sources reveals their degree of relatedness. The U.S. Crime Act of 1994 and similar laws in other countries have mandated archival storage of DNA fingerprints of those convicted of certain crimes.

DNA fingerprinting

n. See DNA profiling.

The analysis of short, highly specific, tandem-repeated—or hypervariable— genomic sequences, minisatellites known as variable number of tandem repeats (VNTRs), to detect the degree of relatedness to another sequence of oligonucleotides. This method of isolating and visualising of sequences of DNA was developed in 1984 by Alec Jeffreys, who identified minisatellites that do not contribute to gene function but are repeated in the genes and elsewhere in a DNA sample, thus providing highly specific information about that organism or person.

DNA fin·ger·print·ing

(fing'gĕr-print'ing) A technique used to compare people using molecular genotyping. DNA is isolated from a specific person, digested, and fractionated according to size. A Southern hybridization with a radiolabeled repetitive DNA probe provides an autoradiographic pattern unique to that person. DNA fingerprinting offers a statistical basis for evaluating the probability that samples of blood, hair, semen, or tissue have originated from a given individual.

DNA fingerprinting

The recording of a pattern of bands on transparent film, corresponding to the unique sequence of regions in the DNA (core sequences) of an individual. DNA fragments, obtained from a DNA sample by cutting it with restriction enzymes, are separated on a sheet of gel by ELECTROPHORESIS. The fragments are then denatured into single strands and the gel is blotted onto a membrane of nylon or nitrocellulose which fixes the fragments in place. Radioactive probes, complementary to the core sequences, are then added. These bind to any fragment containing the core sequence. The membrane is laid on a sheet of photographic film and a pattern of bands is produced by the action of the radiation. The arrangement of the banding pattern is unique to each unrelated person but parents and their offspring have common features. Patterns from different individuals, or from different samples from the same individual can be compared. The method can be used as a means of positive identification or of paternity testing. Only a tiny sample of blood, semen or of any body tissue is needed to provide the DNA.

DNA fingerprinting

see FINGERPRINTING.

DNA fin·ger·print·ing

(fing'gĕr-print'ing) A technique used to compare people using molecular genotyping.

单词	dna fingerprinting
释义	DNA fingerprinting DNA fingerprinting n. See DNA profiling. DNA fingerprinting n. the use of a DNA probe for the identification of an individual, as for the matching of genes from a forensic sample with those of a criminal suspect. Also called genetic fingerprinting. [1985–90] DNA fingerprint, n. DNA fingerprinting The use of a sample of DNA to determine the identity of a person within a certain probability. DNA fingerprinting is done by analyzing repeating patterns of base pairs in DNA sequences that are known to vary greatly among individuals. DNA fingerprinting DNA fingerprinting or DNA profiling, any of several similar techniques for analyzing and comparing DNA from separate sources, used especially in law enforcement to identify suspects from hair, blood, semen, or other biological materials found at the scene of a violent crime. It depends on the fact that no two people, save identical twins, have exactly the same DNA sequence, and that although only limited segments of a person's DNA are scrutinized in the procedure, those segments will be statistically unique. Methods A common procedure for DNA fingerprinting is restriction fragment length polymorphism (RFLP). In this method, DNA is extracted from a sample and cut into segments using special restriction enzymes. RFLP focuses on segments that contain sequences of repeated DNA bases, which vary widely from person to person. The segments are separated using a laboratory technique called electrophoresis, which sorts the fragments by length. The segments are radioactively tagged to produce a visual pattern known as an autoradiograph, or "DNA fingerprint," on X-ray film. A newer method known as short tandem repeats (STR) analyzes DNA segments for the number of repeats at 13 specific DNA sites. The chance of misidentification in this procedure is one in several billion. Yet another process, polymerase chain reactionpolymerase chain reaction (PCR), laboratory process in which a particular DNA segment from a mixture of DNA chains is rapidly replicated, producing a large, readily analyzed sample of a piece of DNA; the process is sometimes called DNA amplification. ..... Click the link for more information. , is used to produce multiple copies of segments from a very limited amount of DNA (as little as 50 molecules), enabling a DNA fingerprint to be made from a single hair. Once a sufficient sample has been produced, the pattern of the alleles (see geneticsgenetics, scientific study of the mechanism of heredity. While Gregor Mendel first presented his findings on the statistical laws governing the transmission of certain traits from generation to generation in 1856, it was not until the discovery and detailed study of the ..... Click the link for more information. ) from a limited number of genes is compared with the pattern from the reference sample. A nonmatch is conclusive, but the technique provides less certainty when a match occurs. Applications In criminal investigations, the DNA fingerprint of a suspect's blood or other body material is compared to that of the evidence from the crime scene to see how closely they match. The technique can also be used to establish paternity. First developed in 1984 by Alec Jeffreys, a British professor of genetics at the Univ. of Leicester, DNA fingerprinting has been accepted in most courts in the United States, and has in several notable instances been used to exonerate or free persons convicted of crimes, but the Supreme Court has ruled (2009) that convicted criminals do not have a constitutional right to DNA testing. All states have established DNA fingerprint databases and require the collection of DNA from convicted felons, and the Federal Bureau of Investigation has instituted a national DNA fingerprint database linking those of the states and including DNA collected in connection with federal offenses. DNA fingerprinting is generally regarded as a reliable forensic tool when properly done, but some scientists have called for wider sampling of human DNA to insure that the segments analyzed are indeed highly variable for all ethnic and racial groups. It is possible to create false genetic samples and use them to misdirect forensic investigators, but if those samples have been produced using gene amplification techniques they can be distinguished from normal DNA evidence. The techniques used in DNA fingerprinting also have applications in paleontology, archaeology, various fields of biology, and medical diagnostics. It has, for example, been used to match the goatskin fragments of the Dead Sea Scrolls. In biological classificationclassification, in biology, the systematic categorization of organisms into a coherent scheme. The original purpose of biological classification, or systematics, was to organize the vast number of known plants and animals into categories that could be named, remembered, and ..... Click the link for more information. , it can help to show evolutionary change and relationships on the molecular level, and it has the advantage of being able to be used even when only very small samples, such as tiny pieces of preserved tissue from extinct animals, are available. Bibliography See D. H. Kaye, The Double Helix and the Law of Evidence (2010). DNA fingerprinting [‚dē‚en′ā ′fiŋ·gər‚print·iŋ] (genetics) genetic fingerprinting DNA fingerprinting DNA fin·ger·print·ing a technique used to compare individuals by molecular genotyping. DNA isolated from a biologic specimen is digested and fractionated. Southern hybridization with a radiolabeled repetitive DNA provides an autoradiographic pattern unique to the individual. Synonym(s): DNA profiling, DNA typing DNA fingerprinting depends on the detection of distinctive DNA sequences in human cellular material (skin, hair, blood, semen). The principal applications of this technique, all of which are based on the premise that no two people have exactly the same genetic makeup, are in determining paternity and maternity, identifying human remains, and matching biologic material left at a crime scene with that of a suspect. The most distinctive features of a person's genome are not the genes themselves but variations in the length and distribution of nongenetic material between gene loci. Although these do not transmit genetic information, they are highly consistent within the cells of each person and highly variable from one person to another. Distinctive nucleotide sequences that are most useful in DNA fingerprinting are variable number tandem repeats (VNTRs) and short tandem repeats (STRs). In DNA fingerprinting, the specimen is split into nucleotide fragments by treatment with restriction enzymes and then subjected to gel electrophoresis so as to yield a characteristic pattern of banding. Radioactive probes, composed of short nucleotide sequences (10-15 base pairs for VNTRs, 3-4 pairs for STRs), then identify sites of tandem repeats and hybridize with them. Comparing the results from two or more DNA sources reveals their degree of relatedness. The U.S. Crime Act of 1994 and similar laws in other countries have mandated archival storage of DNA fingerprints of those convicted of certain crimes. DNA fingerprinting n. See DNA profiling. The analysis of short, highly specific, tandem-repeated—or hypervariable— genomic sequences, minisatellites known as variable number of tandem repeats (VNTRs), to detect the degree of relatedness to another sequence of oligonucleotides. This method of isolating and visualising of sequences of DNA was developed in 1984 by Alec Jeffreys, who identified minisatellites that do not contribute to gene function but are repeated in the genes and elsewhere in a DNA sample, thus providing highly specific information about that organism or person. DNA fin·ger·print·ing (fing'gĕr-print'ing) A technique used to compare people using molecular genotyping. DNA is isolated from a specific person, digested, and fractionated according to size. A Southern hybridization with a radiolabeled repetitive DNA probe provides an autoradiographic pattern unique to that person. DNA fingerprinting offers a statistical basis for evaluating the probability that samples of blood, hair, semen, or tissue have originated from a given individual. DNA fingerprinting The recording of a pattern of bands on transparent film, corresponding to the unique sequence of regions in the DNA (core sequences) of an individual. DNA fragments, obtained from a DNA sample by cutting it with restriction enzymes, are separated on a sheet of gel by ELECTROPHORESIS. The fragments are then denatured into single strands and the gel is blotted onto a membrane of nylon or nitrocellulose which fixes the fragments in place. Radioactive probes, complementary to the core sequences, are then added. These bind to any fragment containing the core sequence. The membrane is laid on a sheet of photographic film and a pattern of bands is produced by the action of the radiation. The arrangement of the banding pattern is unique to each unrelated person but parents and their offspring have common features. Patterns from different individuals, or from different samples from the same individual can be compared. The method can be used as a means of positive identification or of paternity testing. Only a tiny sample of blood, semen or of any body tissue is needed to provide the DNA. DNA fingerprinting see FINGERPRINTING. DNA fin·ger·print·ing (fing'gĕr-print'ing) A technique used to compare people using molecular genotyping. ThesaurusSeeDNA fingerprint
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