Concept
Plasmid
Related concepts (36)
Selectable marker
A selectable marker is a gene introduced into a cell, especially a bacterium or to cells in culture, that confers a trait suitable for artificial selection. They are a type of reporter gene used in laboratory microbiology, molecular biology, and genetic engineering to indicate the success of a transfection or other procedure meant to introduce foreign DNA into a cell. Selectable markers are often antibiotic resistance genes (An antibiotic resistance marker is a gene that produces a protein that provides cells expressing this protein with resistance to an antibiotic.
Virulence
Virulence is a pathogen's or microorganism's ability to cause damage to a host. In most, especially in animal systems, virulence refers to the degree of damage caused by a microbe to its host. The pathogenicity of an organism—its ability to cause disease—is determined by its virulence factors. In the specific context of gene for gene systems, often in plants, virulence refers to a pathogen's ability to infect a resistant host. The noun virulence derives from the adjective virulent, meaning disease severity.
Capsid
A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The proteins making up the capsid are called capsid proteins or viral coat proteins (VCP). The capsid and inner genome is called the nucleocapsid. Capsids are broadly classified according to their structure.
Cloning vector
A cloning vector is a small piece of DNA that can be stably maintained in an organism, and into which a foreign DNA fragment can be inserted for cloning purposes. The cloning vector may be DNA taken from a virus, the cell of a higher organism, or it may be the plasmid of a bacterium. The vector contains features that allow for the convenient insertion of a DNA fragment into the vector or its removal from the vector, for example through the presence of restriction sites.
Multiple cloning site
A multiple cloning site (MCS), also called a polylinker, is a short segment of DNA which contains many (up to ~20) restriction sites - a standard feature of engineered plasmids. Restriction sites within an MCS are typically unique, occurring only once within a given plasmid. The purpose of an MCS in a plasmid is to allow a piece of DNA to be inserted into that region. An MCS is found in a variety of vectors, including cloning vectors to increase the number of copies of target DNA, and in expression vectors to create a protein product.
Ligation (molecular biology)
Ligation is the joining of two nucleic acid fragments through the action of an enzyme. It is an essential laboratory procedure in the molecular cloning of DNA, whereby DNA fragments are joined to create recombinant DNA molecules (such as when a foreign DNA fragment is inserted into a plasmid). The ends of DNA fragments are joined by the formation of phosphodiester bonds between the 3'-hydroxyl of one DNA terminus with the 5'-phosphoryl of another. RNA may also be ligated similarly.
Restriction digest
A restriction digest is a procedure used in molecular biology to prepare DNA for analysis or other processing. It is sometimes termed DNA fragmentation, though this term is used for other procedures as well. In a restriction digest, DNA molecules are cleaved at specific restriction sites of 4-12 nucleotides in length by use of restriction enzymes which recognize these sequences. The resulting digested DNA is very often selectively amplified using polymerase chain reaction (PCR), making it more suitable for analytical techniques such as agarose gel electrophoresis, and chromatography.
Electroporation
Electroporation, or electropermeabilization, is a microbiology technique in which an electrical field is applied to cells in order to increase the permeability of the cell membrane, allowing chemicals, drugs, electrode arrays or DNA to be introduced into the cell (also called electrotransfer). In microbiology, the process of electroporation is often used to transform bacteria, yeast, or plant protoplasts by introducing new coding DNA.
Natural competence
In microbiology, genetics, cell biology, and molecular biology, competence is the ability of a cell to alter its genetics by taking up extracellular ("naked") DNA from its environment in the process called transformation. Competence may be differentiated between natural competence, a genetically specified ability of bacteria which is thought to occur under natural conditions as well as in the laboratory, and induced or artificial competence, which arises when cells in laboratory cultures are treated to make them transiently permeable to DNA.
Rolling circle replication
Rolling circle replication (RCR) is a process of unidirectional nucleic acid replication that can rapidly synthesize multiple copies of circular molecules of DNA or RNA, such as plasmids, the genomes of bacteriophages, and the circular RNA genome of viroids. Some eukaryotic viruses also replicate their DNA or RNA via the rolling circle mechanism. As a simplified version of natural rolling circle replication, an isothermal DNA amplification technique, rolling circle amplification was developed.