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Nuclear Run-on
A nuclear run-on assay is conducted to identify the genes that are being transcribed at a certain time point. Approximately one million cell nuclei are isolated and incubated with labeled nucleotides, and genes in the process of being transcribed are detected by hybridization of extracted RNA to gene specific probes on a blot. Garcia-Martinez et al. (2004) developed a protocol for the yeast ''S. cerevisiae'' (Genomic run-on, GRO) that allows for the calculation of transcription rates (TRs) for all yeast genes to estimate mRNA stabilities for all yeast mRNAs. Alternative microarray methods have recently been developed, mainly PolII RIP-chip: RNA immunoprecipitation of RNA polymerase II with phosphorylated C-terminal domain directed antibodies and hybridization on a microarray slide or chip (the word chip in the name stems from "ChIP-chip" where a special Affymetrix Affymetrix is now Applied Biosystems, a brand of DNA microarray products sold by Thermo Fisher Scientific that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription (genetics)
Transcription is the process of copying a segment of DNA into RNA. The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). Other segments of DNA are copied into RNA molecules called non-coding RNAs (ncRNAs). mRNA comprises only 1–3% of total RNA samples. Less than 2% of the human genome can be transcribed into mRNA ( Human genome#Coding vs. noncoding DNA), while at least 80% of mammalian genomic DNA can be actively transcribed (in one or more types of cells), with the majority of this 80% considered to be ncRNA. Both DNA and RNA are nucleic acids, which use base pairs of nucleotides as a complementary language. During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, antiparallel RNA strand called a primary transcript. Transcription proceeds in the following general steps: # RNA polymerase, together with one or more general transcription factors, binds to promoter DNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Nucleus
The cell nucleus (pl. nuclei; from Latin or , meaning ''kernel'' or ''seed'') is a membrane-bound organelle found in eukaryotic cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a few others including osteoclasts have many. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm; and the nuclear matrix, a network within the nucleus that adds mechanical support. The cell nucleus contains nearly all of the cell's genome. Nuclear DNA is often organized into multiple chromosomes – long stands of DNA dotted with various proteins, such as histones, that protect and organize the DNA. The genes within these chromosomes are structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the cell by regulating gene expres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleotide
Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all life-forms on Earth. Nucleotides are obtained in the diet and are also synthesized from common nutrients by the liver. Nucleotides are composed of three subunit molecules: a nucleobase, a five-carbon sugar (ribose or deoxyribose), and a phosphate group consisting of one to three phosphates. The four nucleobases in DNA are guanine, adenine, cytosine and thymine; in RNA, uracil is used in place of thymine. Nucleotides also play a central role in metabolism at a fundamental, cellular level. They provide chemical energy—in the form of the nucleoside triphosphates, adenosine triphosphate (ATP), guanosine triphosphate (GTP), cytidine triphosphate (CTP) and uridine triphosphate (UTP)—throughout the cell for the many cellular func ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blot (biology)
A blot, in molecular biology and genetics, is a method of transferring proteins, DNA or RNA onto a carrier (for example, a nitrocellulose, polyvinylidene fluoride or nylon membrane). In many instances, this is done after a gel electrophoresis, transferring the molecules from the gel onto the Blotting matrix, blotting membrane, and other times adding the samples directly onto the membrane. After the blotting, the transferred proteins, DNA or RNA are then visualized by colorant staining (for example, silver staining of proteins), autoradiographic visualization of radioactive tracer, radiolabelled molecules (performed before the blot), or specific labelling of some proteins or nucleic acids. The latter is done with antibody, antibodies or hybridization probes that bind only to some molecules of the blot and have an enzyme joined to them. After proper washing, this enzymatic activity (and so, the molecules we search in the blot) is visualized by incubation with proper reactive, renderin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNA Immunoprecipitation
Immunoprecipitation (IP) is the technique of precipitating a protein antigen out of solution using an antibody that specifically binds to that particular protein. This process can be used to isolate and concentrate a particular protein from a sample containing many thousands of different proteins. Immunoprecipitation requires that the antibody be coupled to a solid substrate at some point in the procedure. Types Individual protein immunoprecipitation (IP) Involves using an antibody that is specific for a known protein to isolate that particular protein out of a solution containing many different proteins. These solutions will often be in the form of a crude lysate of a plant or animal tissue. Other sample types could be body fluids or other samples of biological origin. Protein complex immunoprecipitation (Co-IP) Immunoprecipitation of intact protein complexes (i.e. antigen along with any proteins or ligands that are bound to it) is known as co-immunoprecipitation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Affymetrix
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. In 1994, the company's first product under the "GeneChip" Affymetrix trademark, an HIV genotyping chip was introduced, and the company went public in 1996. After incorporation, Affymetrix grew in part by acquiring technologies from other companies, including Genetic MicroSystems (slide-based Microarrays and scanners) and Neomorphic (for bioinformatics) in 2000, ParAllele Bioscience (custom SNP genotyping), USB/Anatrace (biochemical reagents) in 2008, Panomics (low to mid-pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarkosyl
Sodium lauroyl sarcosinate ( INCI), also known as sarcosyl, is an anionic surfactant derived from sarcosine used as a foaming and cleansing agent in shampoo, shaving foam, toothpaste, and foam wash products. This surfactant is amphiphilic due to the hydrophobic 12-carbon chain ( lauroyl) and the hydrophilic carboxylate. Since the nitrogen atom is in an amide linkage, the nitrogen is not pH active and is neutrally charged in all aqueous solutions regardless of pH. The carboxylate has a pKa of about 3.6 and is therefore negatively charged in solutions of pH greater than about 5.5. pH-sensitive vesicles can be prepared using this surfactant with another cationic or water-insoluble amphiphiles such as 1-decanol. Addition of an mixture of equal parts of sodium lauroyl sarcosinate and the non-ionic surfactant sorbitan monolaurate (S20) to water led to the formation of micelle-like aggregates, even though neither surfactant formed micelles when present alone. Such aggregat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Expression
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, protein or non-coding RNA, and ultimately affect a phenotype, as the final effect. These products are often proteins, but in non-protein-coding genes such as transfer RNA (tRNA) and small nuclear RNA (snRNA), the product is a functional non-coding RNA. Gene expression is summarized in the central dogma of molecular biology first formulated by Francis Crick in 1958, further developed in his 1970 article, and expanded by the subsequent discoveries of reverse transcription and RNA replication. The process of gene expression is used by all known life—eukaryotes (including multicellular organisms), prokaryotes (bacteria and archaea), and utilized by viruses—to generate the macromolecular machinery for life. In genetics, gene expression is the most fundamental level at which the genotype gives rise to the phenotype, '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
