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Taxonomic Resolution
DNA barcoding is a method of species identification using a short section of DNA from a specific gene or genes. The premise of DNA barcoding is that by comparison with a reference library of such DNA sections (also called "sequences"), an individual sequence can be used to uniquely identify an organism to species, just as a supermarket scanner uses the familiar black stripes of the UPC barcode to identify an item in its stock against its reference database. These "barcodes" are sometimes used in an effort to identify unknown species or parts of an organism, simply to catalog as many taxa as possible, or to compare with traditional taxonomy in an effort to determine species boundaries. Different gene regions are used to identify the different organismal groups using barcoding. The most commonly used barcode region for animals and some protists is a portion of the cytochrome ''c'' oxidase I (COI or COX1) gene, found in mitochondrial DNA. Other genes suitable for DNA barcoding are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Mapping
Optical mapping is a technique for constructing ordered, genome-wide, high-resolution restriction maps from single, stained molecules of DNA, called "optical maps". By mapping the location of restriction enzyme sites along the unknown DNA of an organism, the spectrum of resulting DNA fragments collectively serves as a unique "fingerprint" or "barcode" for that sequence. Originally developed by Dr. David C. Schwartz and his lab at NYU in the 1990s Schwartz, D. C., et al. "Ordered Restriction Maps of Saccharomyces Cerevisiae Chromosomes Constructed by Optical Mapping." Science 262.5130 (1993): 110–4. this method has since been integral to the assembly process of many large-scale sequencing projects for both microbial and eukaryotic genomes. Later technologies use DNA melting, DNA competitive binding or enzymatic labelling in order to create the optical mappings. Technology The modern optical mapping platform works as follows:Dimalanta, E.T. ''et al.'' A microfluidic system for la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollen DNA Barcoding
Pollen DNA barcoding is the process of identifying pollen donor plant species through the amplification and sequencing of specific, conserved regions of plant DNA. Being able to accurately identify pollen has a wide range of applications though it has been difficult in the past due to the limitations of microscopic identification of pollen. Pollen identified using DNA barcoding involves the specific targeting of gene regions that are found in most to all plant species but have high variation between members of different species. The unique sequence of base pairs for each species within these target regions can be used as an identifying feature. The applications of pollen DNA barcoding range from forensics, to food safety, to conservation. Each of these fields benefits from the creation of plant barcode reference libraries. These libraries range largely in size and scope of their collections as well as what target region(s) they specialize in. One of the main challenges of ident ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base Pair
A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA and RNA. Dictated by specific hydrogen bonding patterns, "Watson–Crick" (or "Watson–Crick–Franklin") base pairs (guanine–cytosine and adenine–thymine) allow the DNA helix to maintain a regular helical structure that is subtly dependent on its nucleotide sequence. The Complementarity (molecular biology), complementary nature of this based-paired structure provides a Redundancy (information theory), redundant copy of the genetic information encoded within each strand of DNA. The regular structure and data redundancy provided by the DNA double helix make DNA well suited to the storage of genetic information, while base-pairing between DNA and incoming nucleotides provides the mechanism through which DNA polymerase replicates DNA and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequencing
In genetics and biochemistry, sequencing means to determine the primary structure (sometimes incorrectly called the primary sequence) of an unbranched biopolymer. Sequencing results in a symbolic linear depiction known as a sequence which succinctly summarizes much of the atomic-level structure of the sequenced molecule. DNA sequencing DNA sequencing is the process of determining the nucleotide order of a given DNA fragment. So far, most DNA sequencing has been performed using the chain termination method developed by Frederick Sanger. This technique uses sequence-specific termination of a DNA synthesis reaction using modified nucleotide substrates. However, new sequencing technologies such as pyrosequencing are gaining an increasing share of the sequencing market. More genome data are now being produced by pyrosequencing than Sanger DNA sequencing. Pyrosequencing has enabled rapid genome sequencing. Bacterial genomes can be sequenced in a single run with several times cov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Amplification
Gene amplification refers to a number of natural and artificial processes by which the number of copies of a gene is increased "without a proportional increase in other genes". Artificial DNA amplification In research or diagnosis DNA amplification can be conducted through methods such as: * Polymerase chain reaction, an easy, cheap, and reliable way to repeatedly replicate a focused segment of DNA by polymerizing nucleotides, a concept which is applicable to numerous fields in modern biology and related sciences. * Ligase chain reaction, a method that amplifies the nucleic acid used as the probe. For each of the two DNA strands, two partial probes are ligated to form the actual one; thus, LCR uses two enzymes: a DNA polymerase (used for initial template amplification and then inactivated) and a thermostable DNA ligase. * Transcription-mediated amplification, an isothermal, single-tube nucleic acid amplification system utilizing two enzymes, RNA polymerase and reverse transcripta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymerase Chain Reaction
The polymerase chain reaction (PCR) is a method widely used to make millions to billions of copies of a specific DNA sample rapidly, allowing scientists to amplify a very small sample of DNA (or a part of it) sufficiently to enable detailed study. PCR was invented in 1983 by American biochemist Kary Mullis at Cetus Corporation. Mullis and biochemist Michael Smith (chemist), Michael Smith, who had developed other essential ways of manipulating DNA, were jointly awarded the Nobel Prize in Chemistry in 1993. PCR is fundamental to many of the procedures used in genetic testing and research, including analysis of Ancient DNA, ancient samples of DNA and identification of infectious agents. Using PCR, copies of very small amounts of DNA sequences are exponentially amplified in a series of cycles of temperature changes. PCR is now a common and often indispensable technique used in medical laboratory research for a broad variety of applications including biomedical research and forensic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Extraction
The first isolation of deoxyribonucleic acid (DNA) was done in 1869 by Friedrich Miescher. DNA extraction is the process of isolating DNA from the cells of an organism isolated from a sample, typically a biological sample such as blood, saliva, or tissue. It involves breaking open the cells, removing proteins and other contaminants, and purifying the DNA so that it is free of other cellular components. The purified DNA can then be used for downstream applications such as PCR, sequencing, or cloning. Currently, it is a routine procedure in molecular biology or forensic analyses. This process can be done in several ways, depending on the type of the sample and the downstream application, the most common methods are: mechanical, chemical and enzymatic lysis, precipitation, purification, and concentration. The specific method used to extract the DNA, such as phenol-chloroform extraction, alcohol precipitation, or silica-based purification. For the chemical method, many different k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Environmental DNA
Environmental DNA or eDNA is DNA that is collected from a variety of environmental samples such as soil, seawater, snow or air, rather than directly sampled from an individual organism. As various organisms interact with the environment, DNA is expelled and accumulates in their surroundings from various sources. Such eDNA can be DNA sequencing#High-throughput methods, sequenced by environmental omics to reveal facts about the species that are present in an ecosystem — even microscopic ones not otherwise apparent or detectable. In recent years, eDNA has been used as a tool to detect endangered wildlife that were otherwise unseen. In 2020, human health researchers began repurposing eDNA techniques to track the COVID-19 pandemic. Example sources of eDNA include, but are not limited to, feces, mucus, gametes, Moulting, shed skin, Carrion, carcasses and hair. Samples can be analyzed by High throughput sequencing, high-throughput DNA sequencing methods, known as metagenomics, Mic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxonomic Group
In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion, especially in the context of rank-based (" Linnaean") nomenclature (much less so under phylogenetic nomenclature). If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were presumably set forth in prehistoric times by hunter-gatherers, as suggested by the fairly sophisticated folk taxonomies. Much later, Aristotle, and later still ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primer (molecular Biology)
A primer is a short, single-stranded nucleic acid used by all living organisms in the initiation of DNA synthesis. A synthetic primer is a type of oligo, short for oligonucleotide. DNA polymerases (responsible for DNA replication) are only capable of adding nucleotides to the 3’-end of an existing nucleic acid, requiring a primer be bound to the template before DNA polymerase can begin a complementary strand. DNA polymerase adds nucleotides after binding to the RNA primer and synthesizes the whole strand. Later, the RNA strands must be removed accurately and replaced with DNA nucleotides. This forms a gap region known as a nick that is filled in using a ligase. The removal process of the RNA primer requires several enzymes, such as Fen1, Lig1, and others that work in coordination with DNA polymerase, to ensure the removal of the RNA nucleotides and the addition of DNA nucleotides. Living organisms use solely RNA primers, while laboratory techniques in biochemistry and mole ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canada
Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of countries and dependencies by area, second-largest country by total area, with the List of countries by length of coastline, world's longest coastline. Its Canada–United States border, border with the United States is the world's longest international land border. The country is characterized by a wide range of both Temperature in Canada, meteorologic and Geography of Canada, geological regions. With Population of Canada, a population of over 41million people, it has widely varying population densities, with the majority residing in List of the largest population centres in Canada, urban areas and large areas of the country being sparsely populated. Canada's capital is Ottawa and List of census metropolitan areas and agglomerations in Canada, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ontario
Ontario is the southernmost Provinces and territories of Canada, province of Canada. Located in Central Canada, Ontario is the Population of Canada by province and territory, country's most populous province. As of the 2021 Canadian census, it is home to 38.5% of the country's population, and is the second-largest province by total area (after Quebec). Ontario is Canada's fourth-largest jurisdiction in total area of all the Canadian provinces and territories. It is home to the nation's capital, Ottawa, and its list of the largest municipalities in Canada by population, most populous city, Toronto, which is Ontario's provincial capital. Ontario is bordered by the province of Manitoba to the west, Hudson Bay and James Bay to the north, and Quebec to the east and northeast. To the south, it is bordered by the U.S. states of (from west to east) Minnesota, Michigan, Ohio, Pennsylvania, and New York (state), New York. Almost all of Ontario's border with the United States follows riv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
