An assay is a procedure in molecular biology Molecular biology is the study of biology at a molecular level. The field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry. Molecular biology chiefly concerns itself with understanding the interactions between the various systems of a cell, including the interactions between DNA, RNA and protein for testing and/or measuring the activity of a drug A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage or biochemical Biochemistry is the study of the chemical processes in living organisms. It deals with the structure and function of cellular components such as proteins, carbohydrates, lipids, nucleic acids and other biomolecules in an organism The term "organism" first appeared in the English language in 1701 and took on its current definition by 1834 (Oxford English Dictionary) or organic sample In general, a sample is a limited quantity of something which is intended to be similar to and represent a larger amount of that thing. The things could be countable objects such as individual items available as units for sale, or a material not countable as individual items. Samples of countable things are discussed in the article Sample. This.[1][2] A quantitative assay may also measure the amount of a substance in a sample. Bioassays Bioassay , or biological standardisation is a type of scientific experiment. Bioassays are essential in the development of new drugs, and in monitoring environmental pollutants. Both are procedures by which the potency or the nature of a substance is estimated by studying its effects on living matter and immunoassays An immunoassay is a biochemical test that measures the concentration of a substance in a biological liquid, typically serum or urine, using the reaction of an antibody or antibodies to its antigen. The assay takes advantage of the specific binding of an antibody to its antigen. Monoclonal antibodies are often used as they only usually bind to one are among the many varieties of specialized biochemical assays. Other assays measure processes such as enzyme Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process are called substrates, and the enzyme converts them into different molecules, called the products. Almost all processes in a biological cell need enzymes to occur at significant rates. Since enzymes are selective for their activity, antigen capture, stem cell Stem cells are cells found in most, if not all, multi-cellular organisms. They are characterized by the ability to renew themselves through mitotic cell division and differentiating into a diverse range of specialized cell types. Research in the stem cell field grew out of findings by Canadian scientists Ernest A. McCulloch and James E. Till in activity, and competitive protein Proteins are organic compounds made of amino acids arranged in a linear chain and folded into a globular form. The amino acids in a polymer are joined together by the peptide bonds between the carboxyl and amino groups of adjacent amino acid residues. The sequence of amino acids in a protein is defined by the sequence of a gene, which is encoded binding.
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Assay varieties
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Cytotoxicity
A cytotoxicity assay measures how toxic a chemical compound A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together in a defined spatial arrangement by chemical bonds is to cells The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. Some organisms, such as most bacteria, are unicellular . Other organisms, such as humans, are multicellular. (Humans have an estimated 100 trillion.
- MTT assay The MTT assay and the MTS assay are laboratory tests and standard colorimetric assays for measuring the activity of enzymes that reduce MTT or MTS + PMS to formazan, giving a purple color. It can also be used to determine cytotoxicity of potential medicinal agents and other toxic materials, since those agents would result in cell toxicity and
- SRB (Sulforhodamine B Sulforhodamine B or kiton red is a fluorescent dye with uses spanning from laser-induced fluorescence (LIF) to the quantification of cellular proteins of cultured cells. The red, solid, water-soluble dye is primarily used as a polar tracer) assay
DNA
Assays for studying interactions Interaction is a kind of action that occurs as two or more objects have an effect upon one another. The idea of a two-way effect is essential in the concept of interaction, as opposed to a one-way causal effect. A closely related term is interconnectivity, which deals with the interactions of interactions within systems: combinations of many of proteins Proteins are organic compounds made of amino acids arranged in a linear chain and folded into a globular form. The amino acids in a polymer are joined together by the peptide bonds between the carboxyl and amino groups of adjacent amino acid residues. The sequence of amino acids in a protein is defined by the sequence of a gene, which is encoded with DNA Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses. The main role of DNA molecules is the long-term storage of information. DNA is often compared to a set of blueprints or a recipe, or a code, since it contains the instructions needed include:
- DNase footprinting assay A DNase footprinting assay is a DNA footprinting technique from molecular biology/biochemistry that detects DNA-protein interaction using the fact that a protein bound to DNA will often protect that DNA from enzymatic cleavage. This makes it possible to locate a protein binding site on a particular DNA molecule. The method uses an enzyme,
- Filter binding assay In biochemistry, one of the ways to learn about an interaction between two molecules is to determine the binding constant, which is a number that describes the ratio of unbound and bound molecules. This information reveals the affinity between the two molecules and allows prediction of the amount bound given any set of initial conditions
- Gel shift assay An electrophoretic mobility shift assay or mobility shift electrophoresis, also referred as a gel shift assay, gel mobility shift assay, band shift assay, or gel retardation assay, is a common affinity electrophoresis technique used to study protein-DNA or protein-RNA interactions. This procedure can determine if a protein or mixture of proteins
Protein
- Bicinchoninic acid assay The bicinchoninic acid assay is a biochemical assay for determining the total level of protein in a solution, similar to Lowry protein assay, Bradford protein assay or biuret reagent. The total protein concentration is exhibited by a color change of the sample solution from green to purple in proportion to protein concentration, which can then be (BCA assay)
- Bradford protein assay The Bradford protein assay is a spectroscopic analytical procedure used to measure the concentration of protein in a solution. It is subjective, i.e. dependent on the amino acid composition of the measured protein
- Lowry protein assay The Lowry protein assay method combines the reactions of cupric ions with the peptide bonds under alkaline conditions with the oxidation of aromatic protein residues. The Lowry method is best used with protein concentrations of 0.01-1.0 mg/mL. and is based on the reaction of Cu+, produced by the oxidation of peptide bonds, with Folin's reagent (a[3][4]
- Secretion assay Secretion assay is a process used in cell biology to identify cells that are secreting a particular protein . It was first developed by Manz et al. in 1995
RNA
Cell counting
A cell-counting assay, may determine the number of living cells, the number of dead cells, or the ratio of one cell type to another. One example of a cell-counting assay is a blood cell A blood cell is any cell of any type normally found in blood. In mammals, these fall into three general categories: count.
- CASY cell counting technology CASY technology is an electric field multi-channel cell counting system. It was first marketed by Schärfe System GmbH in 1998. In 2006, Schärfe System was acquired by Innovatis, a company focused on cell culture analysis. CASY utilizes the techniques of electric current exclusion and pulse area analysis, the cells can be analyzed and counted in
- Coulter counter
Petrochemistry
Virology
The HPCE-based viral titer assay uses a proprietary, high-performance capillary electrophoresis system to determine baculovirus titer A titer is a measure of concentration. Titer testing employs serial dilution to obtain approximate quantitative information from an analytical procedure that inherently only evaluates as positive or negative. The titer corresponds to the highest dilution factor that still yields a positive reading. For example, positive readings in the first 8.
The Trofile assay is used to determine HIV tropism HIV tropism refers to the cell type that the human immunodeficiency virus infects and replicates in. HIV tropism of a patient's virus is measured by the Trofile assay.
One may use a viral plaque assay to calculate the number of viruses A virus is a small infectious agent that can replicate only inside the cells of other organisms. Viruses are too small to be seen directly with a light microscope. Viruses infect all types of organisms, from animals and plants to bacteria and archaea. Since the initial discovery of tobacco mosaic virus by Martinus Beijerinck in 1898, about 5,000 present in a sample. This technique requires counting the number of plaques formed by a virus sample, from which the actual virus concentration can be determined.
Cellular secretions
A wide range of cellular secretions (say, a specific antibody Antibodies are gamma globulin proteins that are found in blood or other bodily fluids of vertebrates, and are used by the immune system to identify and neutralize foreign objects, such as bacteria and viruses. They are typically made of basic structural units—each with two large heavy chains and two small light chains—to form, for example, or cytokine Cytokines are any of a number of substances that are secreted by specific cells of the immune system which carry signals locally between cells, and thus have an effect on other cells. They are a category of signaling molecules that are used extensively in cellular communication. They are proteins, peptides, or glycoproteins. The term cytokine) can be detected using the ELISA Enzyme-linked immunosorbant assay, also called ELISA, enzyme immunoassay or EIA, is a biochemical technique used mainly in immunology to detect the presence of an antibody or an antigen in a sample. The ELISA has been used as a diagnostic tool in medicine and plant pathology, as well as a quality control check in various industries. In simple technique. The number of cells which secrete those particular substances can be determined using a related technique, the ELISPOT assay.
Drugs
- Testing for Illegal Drugs Drug tests in the United States can be divided into two general groups, federal mandated and general workplace. Federal mandated drug testing started when President Ronald Reagan enacted via executive order, that federal workers refrain from using illegal substances. Subsequent federal legislation required drug testing within the executive branch
- Radioligand binding assay
See also
- Analytical chemistry Analytical chemistry is the study of the chemical composition of natural and artificial materials. Properties studied in analytical chemistry include geometric features such as molecular morphologies and distributions of species, as well as features such as composition and species identity. Unlike the sub disciplines inorganic chemistry and
- CASY cell counting technology CASY technology is an electric field multi-channel cell counting system. It was first marketed by Schärfe System GmbH in 1998. In 2006, Schärfe System was acquired by Innovatis, a company focused on cell culture analysis. CASY utilizes the techniques of electric current exclusion and pulse area analysis, the cells can be analyzed and counted in
- ELISA Enzyme-linked immunosorbant assay, also called ELISA, enzyme immunoassay or EIA, is a biochemical technique used mainly in immunology to detect the presence of an antibody or an antigen in a sample. The ELISA has been used as a diagnostic tool in medicine and plant pathology, as well as a quality control check in various industries. In simple
- MELISA A MELISA test is a blood test that detects Type-IV allergy to metals, chemicals, environmental toxins and molds from one single blood sample. It can also identify active Lyme disease (Lyme Borreliosis). The test does not measure toxicity-that is to say, it will not measure the amounts of a harmful substance in the patient's blood. It measures if
- Multiplex (assay) A multiplex assay is a type of laboratory procedure that simultaneously measures multiple analytes in a single assay. It is distinguished from procedures that measure one or a few analytes at a time. Multiplex assays within a given application area or class of technology can be further stratified based on how many analytes can be measured per
- Pharmaceutical chemistry Medicinal or pharmaceutical chemistry is a discipline at the intersection of chemistry and pharmacology involved with designing, synthesizing and developing pharmaceutical drugs. Medicinal chemistry involves the identification, synthesis and development of new chemical entities suitable for therapeutic use. It also includes the study of existing
- Titration Titration is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of a known reactant. Because volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the titrant or titrator, of a known concentration and volume is used to react with a
References
- ^ The American Heritage Dictionary of the English Language. Fourth Edition. Houghton Mifflin Company: 2000.
- ^ McKean, Erin (ed.). The New Oxford American Dictionary. Second edition. Oxford University Press: 2005.
- ^ Lowry OH, Rosebrough NJ, Farr AL, Randall RJ (November 1951). "Protein measurement with the Folin phenol reagent". J. Biol. Chem. 193 (1): 265–75. PMID A PMID is a unique number assigned to each PubMed citation of life sciences and biomedical scientific journal articles. The related Pubmed Central archive may additionally assign a separate number, a PMCID (PubMed Central Identifier), normally written with a PMC prefix 14907713. http://www.jbc.org/cgi/pmidlookup?view=long&pmid=14907713.
- ^ http://www.animal.ufl.edu/hansen/protocols/LOWRY.htm
Categories: Biochemistry Biochemistry is the chemistry of life. Biochemists study the elements, compounds and chemical reactions that are controlled by biomolecules and take place in all living organisms | Laboratory techniques Laboratory techniques, as used in Biology, Biochemistry, Chemistry, Molecular biology, etc | Titration
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Millipore has launched Milliplex MAP EpiQuant assay panels, a new family of phosphotyrosine multiplex assays for cell signalling research. ...
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hu, 18 Feb 2010 14:20:20 GM
1:37 PM: (KAH) Outstanding Chemical . Assay. Results from Roessin...
Q. people who want me to google and wiki- could pls take the trouble to google and wiki and let me know the answer to my question??
Asked by Meg - Fri Feb 27 06:48:04 2009 - - 3 Answers - 0 Comments
A. i dunno frankly speaking... look in google or wiki
Answered by magandude - Fri Feb 27 06:55:22 2009
