In genetics, complementary DNA (cDNA) is DNA synthesized from a single-stranded RNA template in a reaction catalyzed by the enzyme reverse transcriptase. cDNA is often used to express a specific protein in a cell that does not normally express that protein, or to sequence or quantify mRNA molecules using DNA based methods. cDNA that codes for a specific protein can be transferred to a recipient cell for expression, often bacterial or yeast expression systems. cDNA is also generated to analyze transcriptomic profiles in bulk tissue, single cells, or single nuclei in assays such as microarrays, qPCR, and RNA-seq.
Molecular biology is a branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions.
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 sufficiently to enable detailed study. PCR was invented in 1983 by American biochemist Kary Mullis at Cetus Corporation; Mullis and biochemist Michael Smith, who had developed other essential ways of manipulating DNA; the creation for which they were jointly awarded the Nobel Prize in Chemistry in 1993.
A primer is a short single-stranded nucleic acid used by all living organisms in the initiation of DNA synthesis. A synthetic primer may also be referred to as an oligo, short for oligonucleotide. DNA polymerase enzymes 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 replace them with DNA nucleotides forming a gap region known as a nick that is filled in using an enzyme called 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 molecular biology that require in vitro DNA synthesis usually use DNA primers, since they are more temperature stable. Primers can be designed in laboratory for specific reactions such as polymerase chain reaction (PCR). When designing PCR primers, there are specific measures that must be taken into consideration, like the melting temperature of the primers and the annealing temperature of the reaction itself. Moreover, the DNA binding sequence of the primer in vitro has to be specifically chosen, which is done using a method called basic local alignment search tool (BLAST) that scans the DNA and finds specific and unique regions for the primer to bind.
A restriction enzyme, restriction endonuclease, REase, ENase orrestrictase is an enzyme that cleaves DNA into fragments at or near specific recognition sites within molecules known as restriction sites. Restriction enzymes are one class of the broader endonuclease group of enzymes. Restriction enzymes are commonly classified into five types, which differ in their structure and whether they cut their DNA substrate at their recognition site, or if the recognition and cleavage sites are separate from one another. To cut DNA, all restriction enzymes make two incisions, once through each sugar-phosphate backbone of the DNA double helix.
Molecular genetics is a sub-field of biology that addresses how differences in the structures or expression of DNA molecules manifests as variation among organisms. Molecular genetics often applies an "investigative approach" to determine the structure and/or function of genes in an organism's genome using genetic screens. The field of study is based on the merging of several sub-fields in biology: classical Mendelian inheritance, cellular biology, molecular biology, biochemistry, and biotechnology. Researchers search for mutations in a gene or induce mutations in a gene to link a gene sequence to a specific phenotype. Molecular genetics is a powerful methodology for linking mutations to genetic conditions that may aid the search for treatments/cures for various genetics diseases.
In molecular biology, a library is a collection of DNA fragments that is stored and propagated in a population of micro-organisms through the process of molecular cloning. There are different types of DNA libraries, including cDNA libraries, genomic libraries and randomized mutant libraries. DNA library technology is a mainstay of current molecular biology, genetic engineering, and protein engineering, and the applications of these libraries depend on the source of the original DNA fragments. There are differences in the cloning vectors and techniques used in library preparation, but in general each DNA fragment is uniquely inserted into a cloning vector and the pool of recombinant DNA molecules is then transferred into a population of bacteria or yeast such that each organism contains on average one construct. As the population of organisms is grown in culture, the DNA molecules contained within them are copied and propagated.
Affymetrix is now Applied Biosystems, a brand of DNA microarray products sold by Thermo Fisher Scientific that originated with an American biotechnology research and development and manufacturing company of the same name. The Santa Clara, California-based Affymetrix, Inc. now a part of Thermo Fisher Scientific was co-founded by Alex Zaffaroni and Stephen Fodor. Stephen Fodor and his group, based on their earlier development of methods to fabricate DNA microarrays using semiconductor manufacturing techniques.
Recombinant DNA (rDNA) molecules are DNA molecules formed by laboratory methods of genetic recombination that bring together genetic material from multiple sources, creating sequences that would not otherwise be found in the genome.
Invitrogen is one of several brands under the Thermo Fisher Scientific corporation. The product line includes various subbrands of biotechnology products, such as machines and consumables for polymerase chain reaction, reverse transcription, cloning, culturing, stem cell production, cell therapy, regenerative medicine, immunotherapy, transfection, DNA/RNA purification, diagnostic tests, antibodies, and immunoassays.
QIAGEN is a provider of sample and assay technologies for molecular diagnostics, applied testing, academic and pharmaceutical research. The company operates in more than 35 offices in over 25 countries. QIAGEN N.V., the global corporate headquarter of the QIAGEN group, is located in Venlo, The Netherlands. European, American, and Asian regional headquarters are located in respectively Hilden, Germany; Germantown, Maryland United States; and Shanghai, China. QIAGEN's shares are listed at the NYSE and at the Frankfurt Stock Exchange in the Prime Standard. Thierry Bernard is the company's Chief Executive Officer(CEO). The main operative headquarters are located in Hilden, Germany.
A real-time polymerase chain reaction is a laboratory technique of molecular biology based on the polymerase chain reaction (PCR). It monitors the amplification of a targeted DNA molecule during the PCR, not at its end, as in conventional PCR. Real-time PCR can be used quantitatively and semi-quantitatively.
DNA shuffling, also known as molecular breeding, is an in vitro random recombination method to generate mutant genes for directed evolution and to enable a rapid increase in DNA library size. Three procedures for accomplishing DNA shuffling are molecular breeding which relies on homologous recombination or the similarity of the DNA sequences, restriction enzymes which rely on common restriction sites, and nonhomologous random recombination which requires the use of hairpins. In all of these techniques, the parent genes are fragmented and then recombined.
A molecular-weight size marker, also referred to as a protein ladder, DNA ladder, or RNA ladder, is a set of standards that are used to identify the approximate size of a molecule run on a gel during electrophoresis, using the principle that molecular weight is inversely proportional to migration rate through a gel matrix. Therefore, when used in gel electrophoresis, markers effectively provide a logarithmic scale by which to estimate the size of the other fragments.
New England Biolabs (NEB) produces and supplies recombinant and native enzyme reagents for the life science research, as well as providing products and services supporting genome editing, synthetic biology and next-generation sequencing. NEB also provides free access to research tools such as REBASE, InBASE, and Polbase.
Thermo Fisher Scientific Inc. is an American supplier of analytical instruments, life sciences solutions, specialty diagnostics, laboratory, pharmaceutical and biotechnology services. Based in Waltham, Massachusetts, Thermo Fisher was formed through the merger of Thermo Electron and Fisher Scientific in 2006. Thermo Fisher Scientific has acquired other reagent, consumable, instrumentation, and service providers, including Life Technologies Corporation (2013), Alfa Aesar (2015), Affymetrix (2016), FEI Company (2016), BD Advanced Bioprocessing (2018), and PPD (2021).
Biomolecular engineering is the application of engineering principles and practices to the purposeful manipulation of molecules of biological origin. Biomolecular engineers integrate knowledge of biological processes with the core knowledge of chemical engineering in order to focus on molecular level solutions to issues and problems in the life sciences related to the environment, agriculture, energy, industry, food production, biotechnology and medicine.
The following outline is provided as an overview of and topical guide to genetics:
Molecular cloning is a set of experimental methods in molecular biology that are used to assemble recombinant DNA molecules and to direct their replication within host organisms. The use of the word cloning refers to the fact that the method involves the replication of one molecule to produce a population of cells with identical DNA molecules. Molecular cloning generally uses DNA sequences from two different organisms: the species that is the source of the DNA to be cloned, and the species that will serve as the living host for replication of the recombinant DNA. Molecular cloning methods are central to many contemporary areas of modern biology and medicine.
DEAH-box helicase 8, is a protein that in humans is encoded by the DHX8 gene. This protein is member of the DEAH box polypeptide family. The main characteristic of this group is their conserved motif DEAH. A wide range of RNA helicases belongs to this family. Specifically, DHX8 acts as an ATP-dependent RNA helicase involved in splicing and the regulation of the releasing of spliced mRNAs from spliceosomes out of the nucleus. Published studies have shown the consequences of DHX8 mutations, some of them are critical for biological processes such as hematopoiesis and are related to some diseases.
