Category: DNA profiling techniques

Although now largely obsolete due to the rise of inexpensive DNA sequencing technologies, RFLP analysis was the first DNA profiling technique inexpensive enough to see widespread application.

DNA profiling in 1999 found Syrah to be the offspring of two obscure grapes from southeastern France, Dureza and Mondeuse Blanche.

DNA profiling ( also called DNA testing, DNA typing, or genetic fingerprinting ) is a technique employed by forensic scientists to assist in the identification of individuals by their respective DNA profiles.

DNA profiling should not be confused with full genome sequencing.

DNA profiling uses repetitive (" repeat ") sequences that are highly variable, called variable number tandem repeats ( VNTRs ), particularly short tandem repeats ( STRs ).

The DNA profiling technique was first reported in 1984 by Sir Alec Jeffreys at the University of Leicester in England, and is now the basis of several national DNA databases.

Alec Jeffreys, the pioneer of DNA profiling.

The first methods for finding out genetics used for DNA profiling involved restriction enzyme digestion, followed by Southern blot analysis.

With the invention of the polymerase chain reaction ( PCR ) technique, DNA profiling took huge strides forward in both discriminating power and the ability to recover information from very small ( or degraded ) starting samples.

The method of DNA profiling used today is based on PCR and uses short tandem repeats ( STR ) a type of VNTR.

There are state laws on DNA profiling in all 50 states of the United States.

* In 1986, Richard Buckland was exonerated, despite having admitted to the rape and murder of a teenager near Leicester, the city where DNA profiling was first discovered.

It was the first murder in Australia to be solved using DNA profiling.

Sir Alec John Jeffreys, FRS ( born 9 January 1950 in Oxford, Oxfordshire, England ) is a British geneticist, who developed techniques for DNA fingerprinting and DNA profiling which are now used all over the world in forensic science to assist police detective work, and also to resolve paternity and immigration disputes.

By focussing on just a few of these highly variable minisatellites, DNA profiling made the system more sensitive, more reproducible, and amenable to computer databasing, and soon became the standard forensic DNA system used in criminal case work and paternity testing worldwide.

The present understanding of the Apiales is fairly recent and is based upon comparison of DNA sequences by phylogenetic methods.

This somewhat unsatisfactory state of affairs awaits resolution with DNA based methods.

In 1998 the Angiosperm Phylogeny Group published a phylogeny of flowering plants based on an analysis of DNA sequences from most families of flowering plants.

All known forms of life are based on the same fundamental biochemical organisation: genetic information encoded in DNA, transcribed into RNA, through the effect of protein-and RNA-enzymes, then translated into proteins by ( highly similar ) ribosomes, with ATP, NADH and others as energy sources, etc.

This enzyme operates on a single strand of mRNA, generating its complementary DNA based on the pairing of RNA base pairs ( A, U, G and C ) to their DNA complements ( T, A, C and G respectively ).

Dipsacales phylogeny based on chloroplast DNA sequences.

In 2007, Echols petitioned for a retrial based on a statute permitting post-conviction testing of DNA evidence due to technological advances made since 1994 which might provide exoneration for the wrongfully convicted.

Ward and Brownlee are open to the idea of evolution on other planets which is not based on essential Earth-like characteristics ( such as DNA and carbon ).

The DNA double helix structure proposed by Watson and Crick was based upon " Watson-Crick " bonds between the four bases most frequently found in DNA ( A, C, T, G ) and RNA ( A, C, U, G ).

" Approximate geographic ranges, fur patterns and phylogenetics | phylogenetic relationships between some giraffe subspecies based on mitochondrial DNA sequences.

In 2007, S. Elizabeth Alter used a genetic approach to estimate prewhaling abundance based on samples from 42 California gray whales, and reported DNA variability at 10 genetic loci consistent with a population size of 76, 000 – 118, 000 individuals, three to five times larger than the average census size as measured through 2007.

This was based on the belief that proteins were more complex than DNA.

They made this proposal based on the structural similarity that exists between the two macromolecules, that is, both protein and DNA are linear sequences of amino acids and nucleotides respectively.

Early biochips were based on the idea of a DNA microarray,

The first semblance of Malpighiales as we now know it came from a phylogeny of seed plants published in 1993 and based upon DNA sequences of the gene rbcL.

The diagnosis of muscular dystrophy is based on the results of muscle biopsy, increased creatine phosphokinase ( CpK3 ), electromyography, electrocardiography and DNA analysis.

The modern-day minority of Mongolic-speaking Daurs in China are their direct descendants based on DNA evidence.

For example, one strategy often in use is the artificial production of proteins, based on the genetic code ( DNA ).

No tribes accept DNA testing to satisfy their differing qualifications for membership, usually based on documented blood quantum or descent from ancestor ( s ) listed on the Dawes Rolls.

In contrast, single-stranded RNA and DNA molecules are not constrained to a regular double helix, and can adopt highly complex three-dimensional structures that are based on short stretches of intramolecular base-paired sequences that include both Watson-Crick and noncanonical base pairs, as well as a wide range of complex tertiary interactions.

Forensics teams confirmed that it seemed two of the hijackers were brothers, based on their DNA similarities.

Much research has focused on the relatively few actual cases where innocence was subsequently proven, such as successful appeals for murder and rape based upon DNA evidence, which tend to be atypical of trials as a whole ( being by their nature only the most serious kinds of crime ).

The RNA world hypothesis proposes that self-replicating ribonucleic acid ( RNA ) molecules were precursors to current life, which is based on deoxyribonucleic acid ( DNA ), RNA and proteins.

The order is clearly circumscribed on the basis of DNA sequence analysis, but is difficult to define morphologically, since its members are structurally diverse.

Abzymes are potential tools in biotechnology, e. g., to perform specific actions on DNA.

* Base pair, a pair of connected nucleotides on complementary DNA and RNA strands

While scientists do not always agree on how to classify organisms, molecular phylogenetics, which uses DNA sequences as data, has driven many recent revisions along more efficient, evolutionary lines and is likely to continue to do so.

Instead it generates the sequences of many thousands of small DNA fragments ( ranging from 35 to 900 nucleotides long, depending on the sequencing technology ).

In molecular biology and genetics, the linking between two nitrogenous bases on opposite complementary DNA or certain types of RNA strands that are connected via hydrogen bonds is called a base pair ( often abbreviated bp ).

Other chemicals, known as DNA intercalators, fit into the gap between adjacent bases on a single strand and induce frameshift mutations by " masquerading " as a base, causing the DNA replication machinery to skip or insert additional nucleotides at the intercalated site.

Most of the biosecurity concerns in synthetic biology, however, focused on the role of DNA synthesis and the risk of producing genetic material of lethal viruses ( e. g. 1918 Spanish flu, polio ) in the lab.

Though there is some debate on the exact mechanism of conjugation it seems that the pili are not the structures through which DNA exchange occurs.

The amount of chromosomal DNA that is transferred depends on how long the two conjugating bacteria remain in contact.

In prokaryotes, DNA is usually arranged as a loop, which is tightly coiled in on itself, sometimes accompanied by one or more smaller, circular DNA molecules called plasmids.

The overall structure depends on the stage of the cell cycle: during interphase the chromatin is structurally loose to allow access to RNA and DNA polymerases that transcribe and replicate the DNA.

The local structure of chromatin during interphase depends on the genes present on the DNA: DNA coding genes that are actively transcribed (" turned on ") are more loosely packaged and are found associated with RNA polymerases ( referred to as euchromatin ) while DNA coding inactive genes (" turned off ") are found associated with structural proteins and are more tightly packaged ( heterochromatin ).