, coins metallurgical assay the Communes of France commune in the Indre et Loire Assay, Indre et Loire Wiktionary assay An assay is a procedure in molecular biology for testing or measuring ... University Press 2005. ref A quantitative assay may also measure the amount of a substance in a sample ... protein binding. Assay varieties Unreferenced section date May 2009 Cytotoxicity A cytotoxicity assay measures how toxic a chemical compound is to Cell biology cells . MTT assay SRB Sulforhodamine B assay DNA Assays for studying interaction s of proteins with DNA include DNase footprinting assay Filter binding assay Gel shift assay Protein Bicinchoninic acid assay BCA assay Bradford protein assay Lowry protein assay ref cite journal author Lowry OH, Rosebrough NJ, Farr AL, Randall RJ title ... 14907713 ref ref http www.animal.ufl.edu hansen protocols LOWRY.htm ref Secretion assay RNA Nuclear run on Cell counting, viability, proliferation or cytotoxicity assays A cell counting assay may determine ... , Coulter counter , Electric cell substrate impedance sensing Cell viability assay s Resazurin Cell Viability applications resazurin method , ATP test , Ethidium homodimer assay detect dead or dying cells , Bacteriological water analysis , Clonogenic assay s, ... Surfactants An MBAS assay indicates ... Migration assay s, Chemotaxis assay Secretion assay s Apoptosis assays such as Single Cell Gel Electrophoresis Comet assay Apoptosis DNA fragmentation , Annexin V Chemosensitivity assay measures the number of tumor cells that are killed by a cancer drug Tetramer assay detect the presence of antigen specific T cells Gentamicin protection assay or survival assay or invasion assay to asses ability of pathogens bacteria to invade eukaryotic cells Petrochemistry Crude oil assay Virology The HPCE based viral titer assay uses a proprietary, high performance capillary electrophoresis system to determine baculovirus titer . The Trofile assay is used to determine HIV tropism . The viral plaque ... more details
for the manufacture s mark to be struck by the Assay Office upon submission of the article ... d Pozna Warsaw Wroc aw Polish Assay Offices test and mark precious metal alloy articles gold, silver ...Assay offices are institution s set up to assay test the purity of precious metals, in order to protect consumer consumers . Upon successful completion of an assay, i.e. if the metallurgical content is found ... law the assay offices typically stamp a hallmark , punze , or poin on on the item to certify its ... under Etienne Boileau , Provost of Paris , for Louis IX of France King Louis IX . US assay ... in the United States with United States assay or any similar stamp which gives the impression that the item ... of U.S. assay offices There is no hallmarking scheme in the U.S. yet assay offices did do exist in the U.S. ... assay offices that still operate function solely within national coining system including bullion coinage for sales to investors but are not involved in hallmarking, the end product of the assay which is the subject of this article. There is no hallmarking scheme in the U.S. However, the U.S. assay facilities include ref name treas.gov US assay offices, current The http www.usmint.gov about the mint .... It served as an Assay Office until 1906, when coinage operations began. The http www.usmint.gov ... operations were suspended in March 1955, but the plant continued to operate as an Assay Office. In 1962, its official designation was changed from Mint to Assay Office. Coinage operations were again ... York Assay Office. The Assay Office in Ozark, Arkansas was established in 1835. It has operated as a private club and music venue since the mid 1960s. http www.myspace.com the assay office Jacobs Assay ... establishment in March 1880 in Tucson Arizona Washington Michael Jacobs US assay offices, historical ... as an Assay Office until 1913, when the plant was closed. The New Orleans, Louisiana Mint 1835 to 1942. Coinage operations were conducted here from 1838, but were suspended from 1861 until 1879 assay ... more details
Assay may refer to Assay , a procedure by which the properties of a substance are measured Assay, Indre et Loire , a commune in France disambig eo Provo ... more details
A chemosensitivity assay is a laboratory test that measures the number of tumor cells that are killed by chemotherapy . The test is done after the tumor cells are removed from the body. A chemosensitivity assay may help in choosing the best drug or drugs for the cancer being treated. With dozens of chemotherapy agents and hundreds of combinations available for treatment, oncologists often select a regimen from standard protocols developed in clinical trials. References reflist External links http www.cancer.gov Templates db alpha.aspx?CdrID 45990 Chemosensitivity assay entry in the public domain NCI Dictionary of Cancer Terms NCI cancer dict DEFAULTSORT Chemosensitivity Assay Category Medical tests Category Cancer treatments oncology stub ... more details
Orphan date February 2009 Context date July 2009 A tetramer assay is used to detect the presence of antigen specific T cell s. In order for a T cell to detect the peptide to which it is specific, it must both recognize the peptide AND the MHC complex at the surface of a cell it comes into contact with. Because the binding affinity of a T cell receptor to MHC complexed with a peptide is so low, this has historically been a challenging problem. A solution was realized by creating a tetramer of MHC molecules each presenting an identical peptide. This increases the avidity of the binding. The main component of the assay is an Major histocompatibility complex MHC tetrameric protein tetramer . This reagent has to be custom made for each antigen specific t cell that one desires to detect. The MHC tetramer consists of four units of the MHC molecule each of which is tagged with a biotin molecule. A peptide from the antigen is attached to the MHC molecules. The MHC peptides are made into a complex by the addition typically fluorescently labeled streptavidin , which has an extremely high affinity to biotin. The MHC with its bound peptide will only bind the specific T cells that respond to that peptide. The tetramer can be detected by flow cytometry via the fluorescent label. References cite journal title Phenotypic Analysis of Antigen Specific T Lymphocytes author John D. Altman, Paul A. H. Moss, Philip J. R. Goulder, Dan H. Barouch, Michael G. McHeyzer Williams, John I. Bell, Andrew J. McMichael, Mark M. Davis journal Science date 1996 10 04 volume 274 pages 94 96 url http www.sciencemag.org cgi content full 274 5284 94?ijkey a1ae599b2eec8e0197cb29f5477a32b2a6a5bdbb doi 10.1126 science.274.5284.94 issue 5284 pmid 8810254 biochem stub Category Blood tests ... more details
Unreferenced date December 2009 Orphan date December 2009 An overlay assay is a Biology biological technique used to find protein s that bind to a protein of interest. It begins with proteins that are dispersed but fixed e.g. a tissue slice or run on a membrane by gel electrophoresis and then incubated in the labelled protein of interest. The label will indicate the location of proteins that bind to the protein of interest. DEFAULTSORT Overlay Assay Category Laboratory techniques ... more details
The Trofile TM assay is a blood test that identifies the HIV tropism tropism of a patient s HIV . A molecular assay , Trofile was developed by Monogram Biosciences for use in HIV treatment. The assay s purpose is to identify the HIV tropism tropism of an individual patient s HIV strain R5, X4, or a combination of these known as dual mixed D M . The results show whether the patient is infected with virus that enters cells using the CCR5 R5 co receptor, the CXCR4 X4 co receptor, or both dual mixed . Patients with strains of HIV that prefer the R5 receptor tend to remain healthy longer than those with the strains that prefer X4. However, over the course of the disease, a patient s viral population may undergo a tropism switch from R5 to X4 Fact date June 2009 . References Development and characterization of a novel single cycle recombinant virus assay to determine human immunodeficiency virus type 1 coreceptor tropism. Antimicrob Agents Chemother. 2007 51 2 566 575. Whitcomb JM, Huang W, Fransen S, et al. External links http www.trofileassay.com TrofileAssay.com Monogram Biosciences Trofile assay website http www.medicalnewstoday.com articles 49493.php Four Studies Affirm Significance Of Monogram s Trofile TM HIV Co Receptor Tropism Assay from Medical News Today, August 14, 2006 http www.medicalnewstoday.com articles 64284.php Monogram Provides Update On Trofile TM Assay from Medical News Today, March 2, 2007 http www.medicalnewstoday.com articles 64527.php Scientific Data Highlights Pivotal Role Of Monogram s Molecular Diagnostics In Development And Use Of New HIV Treatments from Medical News Today, March 7, 2007 Category HIV AIDS Category Virology Category Microbiology molecular cell biology stub ... more details
Refimprove date May 2009 Image Tombstone courthouse assay lab.jpg thumb 200px A 19th century assay laboratory ... gold . A metallurgical assay is a compositional analysis of an ore , metal , or alloy . Some assay methods are suitable for raw materials others are more appropriate for finished goods. Raw precious metal s Precious metal Bullion bullion are assayed by an assay office . Silver is assayed by titration ..., Europe s No. 1 Assay Office nl icon Bot generated title ref Precious metal items of art or jewelry ... for 18k gold on the item. In the past the assay was conducted by using the touchstone method but currently ... exacting than the touchstone test. The most exact method of assay is known as fire assay or cupellation. This method is better suited for the assay of bullion and gold stocks rather than works or art ... assay cupellation The most elaborately accurate, but totally destructive, precious metal assay is fire assay. It may also be called by the critical cupellation step that separates precious metal ... an electrolysis test on a gold sample at the Assay office US assay offices United States Assay Office in New York . In the bullion fire assay process, a sample from the article is wrapped in a lead .... Fire assay, as applied to ores, concentrates or less pure metals, adds a fusion or scorification ... to directly analyze precious metals within the lead button. Method details for various fire assay ... of fire assay methodology should be viewed with caution. The standard traditions have a long history of reliability special new methods frequently associate with reduced assay accuracy. Coins A coin assayer is often assigned to each mint coin mint or assay office to determine and assure that all ... and therefore the assay of the raw materials and finished coins is an important quality control. In the UK ... to required standards. Image Goldas 50g silver bullion in assay card.jpg thumb Golda 50g silver bullion in assay card. Notes reflist Further reading Fire assays Bugby, Edward E. A Textbook of Fire ... more details
A methylene blue active substances assay , or MBAS assay , is a colorimetric analysis test method that uses methylene blue to detect the presence of anionic surfactant s such as a detergent or foaming agent in a sample of water . An anionic surfactant detected by the color reaction is called a methylene blue active substance MBAS . ref Alison L. George, Graham F. White Optimization of the methylene blue assay for anionic surfactants added to estuarine and marine water Environmental Toxicology and Chemistry 1999, Volume 18, pages 2232 2236. DOI 10.1002 etc.5620181016 ref After first acidifying a water sample with boric acid , for example , one adds to it chloroform and a solution of methylene blue et al. ref name EUR Lex http eur lex.europa.eu LexUriServ LexUriServ.do?uri CELEX 32004R0648 EN NOT Regulation EC No 648 2004 of the European Parliament and of the Council of 31 March 2004 on detergents ref Methylene blue is a cationic dye . The entire solution is then Agitator device agitated to distribute these reagent s throughout the water sample. ref name EUR Lex The color of the water changes according to the amount of anionic surfactants in the sample. The higher the concentration of surfactants, the deeper and richer the blue coloration. MBAS assay is an ASTM International standard technique for detecting anionic surfactants. ref name astm http www.astm.org Standards D2330.htm ASTM D2330 02 Standard Test Method for Methylene Blue Active Substances ref These include carboxylate s, phosphate s, sulfate s, and sulfonate s. An MBAS assay alone does not, however, identify specific surfactants. ASTM withdrew the standard ASTM D2330 02 in 2011 pending a review and update of the method, which was last approved in 2003. ref name astm . See also Colorimetry Water chemistry analysis Water testing References Reflist Refbegin Nollet, Leo M. L. Handbook of Water Analysis . 2nd ed. New York Marcel Dekker, 2007. Refend DEFAULTSORT MBAS assay Category Analytical chemistry Category Anionic ... more details
For other uses of multiplex, see multiplex disambiguation . A multiplex assay is a type of laboratory procedure that simultaneously measures multiple analyte s dozens or more 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 assay, where multiplex refers to those with the highest number of analyte measurements per assay up to millions and low plex or mid plex refers to procedures that process fewer 10s to 1000s , though there are no formal guidelines for calling a procedure multi , mid , or low plex based on number of analytes measured. Single analyte assays or low to mid plex procedures typically predate the rise of their multiplex versions, which often require specialized technologies or miniaturization to achieve a higher degree of parallelization. Multiplex assays are widely used in functional genomics experiments that endeavor to detect or to assay the state of all biomolecule s of a given class e.g., mRNA s, protein s within a specimen biological sample , to determine the effect of an experimental treatment or the effect of a mutation DNA mutation over all of the biomolecules or metabolic pathway pathway s in the sample. The ability to perform such multiplex assay experiments measuring large numbers of biomolecular analytes has been facilitated by the completion of the Human Genome ... can be analyzed using a multiplex or other assay. Strictly speaking, a multiplex assay is not necessarily high throughput. When the execution of a single multiplex assay generates data for a large number .... Example multiplex assay techniques Nucleic acid based multiplex techniques DNA microarray ... a panel of materials Chemical compound microarray to assay multiple chemical compounds for specific ... pmc 2998181 ref ELISA s are a type of assay that is not multiplex per se because each assay detects ... more details
Refimprove date September 2007 Assay sensitivity is a property of a clinical trial defined as the ability of a trial to distinguish an effective Therapy treatment from a less effective or ineffective intervention. Without assay sensitivity, a trial is not internally valid and is not capable of comparing the efficacy of two interventions. Importance Lack of assay sensitivity has different implications for trials intended to show a difference greater than zero between interventions superiority trials and trials intended to show non inferiority. Non inferiority trials attempt to rule out some margin of inferiority between a test and control intervention i.e. rule out that the test intervention is no worse than the control intervention by a chosen amount. If a trial intended to demonstrate efficacy by showing superiority of a test intervention to Scientific control control lacks assay sensitivity, it will fail to show that the test intervention is superior and will fail to lead to a conclusion of efficacy. In contrast, if a trial intended to demonstrate efficacy by showing a test intervention is non inferior to an active control lacks assay sensitivity, the trial may find an ineffective intervention to be non inferior and could lead to an erroneous conclusion of efficacy. ref cite journal last Snapinn first SM title Noninferiority trials. journal Current controlled trials in cardiovascular ... itself directly demonstrates that the trial had assay sensitivity assuming the finding is not related ... of assay sensitivity. Differences in sensitivity Assay sensitivity for a non inferiority trial ... would have assay sensitivity. On the other hand, with this same data, a noninferiority trial ... may not have assay sensitivity, since this trial would not ensure that the test intervention is any ... Theory, Assay Sensitivity, Choice of Margin date 2002 02 19 accessdate 2007 09 16 url http www.fda.gov ... assay sensitivity, the planned non inferiority trial must be designed in a way similar to the past ... more details
A viability assay is an assay to determine the ability of Cell biology cell s or Tissue biology tissue s to maintain or recover its viability . For example, examining the ratio of potassium to sodium in cells indicates viability. If the cells do not have high intracellular potassium and low intracellular sodium, then 1 the cell membrane may not be intact, and or 2 the Na K ATPase sodium potassium pump may not be operating well ref cite journal author Lindner B, Seydel U title Mass spectrometric analysis of drug induced changes in Na and K contents of single bacterial cells journal Journal of General Microbiology volume 129 issue 1 year 1983 pages 51 55 url http mic.sgmjournals.org cgi reprint 129 1 51 id pmid 633967 ref ref cite journal author Pichugin Y, Fahy GM, Morin R title Cryopreservation of rat hippocampal slices by vitrification journal Cryobiology journal Cryobiology volume 52 issue 2 year 2006 pages 228 240 url http www.21cm.com pdfs hippo published.pdf id pmid 16403489 doi 10.1016 j.cryobiol.2005.11.006 ref As with many kinds of viability assays, quantitative measures of physiological ... dehydrogenase assay, a stable enzyme common in all cells which can be readily detected when cell membranes ... activity or caspase assays Resazurin Cell Viability applications Resazurin and Formazan MTT assay MTT XTT can assay for various stages in the apoptosis process that foreshadow cell death. Functional ..., Motility Cellular level motility motility is a widely used assay of sperm cell function. Fertility can be used to assay gamete survival, in general. Red blood cell s have been assayed in terms of Erythrocyte ... test Calcein Applications Calcein AM Clonogenic assay Ethidium homodimer assay Evans blue Fluorescein ... MTT assay MTT XTT Green fluorescent protein Lactate dehydrogenase LDH Methyl violet Methyl violet ... membranes of dead cells TUNEL assay See also Cytotoxicity Measuring cytotoxicity Cytotoxicity Vital stain References Reflist DEFAULTSORT Viability Assay Category Laboratory techniques Category Microbiology ... more details
The hemagglutination assay or haemagglutination assay HA is a method of quantification for virus es or bacteria by hemagglutination . It is an easy, simple and rapid method which can be applied to large numbers of samples. Some viral families and many bacteria have envelope or surface protein s which are able to agglutinate stick to human or animal red blood cell s RBC and bind to N acetylneuraminic acid . As each of the agglutinating molecule attaches to multiple RBCs, a Bravais lattice lattice structure will form. The hemagglutination assay of a virus, in contrast to other forms of virus quantification such as a plaque assay or 50 Tissue Culture Infective Dose , does not give any measure of viral infectivity, because no virus replication is required in this assay. The same may not be true when using HA for bacteria. The detailed conditions depend on the type of virus or bacteria being assayed since certain pH values and ionic strengths can impact the activity of the proteins of interest in a difficult to predict manner. Normally, a virus dilution e.g. 2 fold from 1 4 to 1 4096 will be applied to an RBC dilution e.g. 0.1 to 0.7 in steps of 0.2 for approx. 30 min, often at 4C, otherwise viruses with neuraminidase activity will detach the virus from the RBCs. Then the lattice forming parts will be counted and the titer calculated. Virus concentration in virion s per Litre milliliter 10 sup 7 sup x HA titer . ref cite journal author Donald HB, Isaacs A title Counts of influenza virus particles journal J. Gen. Microbiol. volume 10 issue 3 pages 457 64 year 1954 pmid 13174769 doi ref The titer of a hemagglutination assay is determined by the last viable lattice structure found. This is because it is at the point where, if diluted anymore, the amount of Virus particles will be less than that of the RBCs and thus not be able to agglutinate them together. For bacteria, depending on species, a bacterial dilution will be applied to an equal part RBC dilution and then incubated ... more details
The Fischer assay is a standardized laboratory test for determining the oil yield from oil shale to be expected from a conventional shale oil extraction . A 100 gram oil shale sample crushed to 2.38 mm is heated in a small aluminum retort to convert 500 C F 1 at a rate of 12 C min 22 F min , and held at that temperature for 40 minutes. ref name dyni Cite paper last Dyni first John R. title Geology and resources of some world oil shale deposits. Scientific Investigations Report 2005 5294 publisher United States Department of the Interior United States Geological Survey year 2006 url http pubs.usgs.gov sir 2005 5294 pdf sir5294 508.pdf format PDF accessdate 2008 08 18 ref The distilled vapors of oil, gas, and water are passed through a Condenser heat transfer condenser and cooled with ice water into a graduated centrifuge tube . The oil yields achieved by other technologies are often reported as a percentage of the Fischer Assay oil yield. The original Fischer Assay test was developed in the early low temperature coal retorting research by Franz Joseph Emil Fischer and Hans Schrader. ref name heistand Cite paper last Heistand first Robert N. title The Fischer Assay, standard method? publisher Symposium on oil shale, tar sands, and related materials production and utilization of synfuels year 1976 location San Francisco url http www.anl.gov PCS acsfuel preprint 20archive Files 21 6 SAN 20FRANCISCO 08 76 0040.pdf format PDF accessdate 2008 08 18 ref It was adapted for evaluating oil shale yields in 1949 by K. E. Stanfield and I. C. Frost. ref cite web author L. Goodfellow, C. E. Haberman and M. T. Atwood publisher Argonne National Laboratory title JOINT SYMPOSIUM ON OIL SHALE, TAR SANDS, AND RELATED MATERIAL AND THE DIVISION OF WATER, AIR, AND WASTE CHEMISTRY ... MEETING, April 2 5, 1968. MODIFIED FISCHER ASSAY EQUIPMENT, PROCEDURES AND PRODUCT BALANCE DETERMINATIONS ... de titrage de Fischer vi Fischer Assay ... more details
A radiobinding assay is a method of detecting and quantifying antibodies targeted towards a specific antigen . As such, it can be seen as the inverse of radioimmunoassay , which quantifies an antigen by use of corresponding antibodies. Technique The corresponding antigen is radiolabel ed and mixed with the fluid that may contain the antibody, such as blood serum from a person. Presence of antibodies cause precipitation of antibody antigen complexes that can be collected by centrifugation into pellets. The amount of antibody is proportional to the radioactivity of the pellet, as determined by gamma counting . ref name perkinelmer http las.perkinelmer.ca content manuals man antidsdnaradiobindingassay.pdf Anti dsDNA & 91 I 125& 93 Radiobinding Assay Kit At PerkinElmer Life Sciences, Inc. Retrieved Jan 2011 ref Uses It is used to detect most autoantibodies seen in latent autoimmune diabetes . ref name knip2005 cite doi 10.2337 diabetes.54.suppl 2.S125 ref References reflist Immunologic techniques and tests medicine stub Category Immunologic tests ... more details
Secretion assay is a process used in cell biology to identify cells that are secretion secreting a particular protein usually a cytokine . It was first developed by Manz et al. in 1995. Usually, a cell that is secreting the protein of interest is isolated using an antibody antibody complex that coats the cell and is able to catch the secreted molecules. The cell is then detected by another fluorochrome labelled antibody , and is subsequently extracted using a process called fluorescent activated cell sorting FACS . The FACS method is broadly similar to the enzyme linked immunosorbent assay ELISA antibody format, except that the encapsulated cells remain intact. This is advantageous as the cells are still living after the extraction has taken place. Further advances now mean that it is possible to extract the secreting cells using a magnetic based separation system or using a flow cytometer . A number of commercial applications exist for secretion assay. One such example is the Gel Microdrop GMD techonology, developed by One Cell Systems . One Cell asserts that GMD typically recovers a higher number of viable secreting cells than other methods, whilst ignoring any cells which are not secreting the desired protein. External links http www.onecell.com GMDProteinSecretionAssay.htm One Cell Systems Gel Microdrop GMD Secretion Assay techonology. Turcanu V, Williams NA http www.nature.com nm journal v7 n3 full nm0301 373.html Cell identification and isolation on the basis of cytokine secretion a novel tool for investigating immune responses Nat Med. 2001 Mar 7 3 373 6 References 1. Manz et al. 1995 Proceedings of the National Academy of Sciences USA Line break Protein methods Category Analytical chemistry Category Cytokines Category Cell biology Category Proteins Cell biology stub ... more details
The S ingle C ell G el E lectrophoresis assay also known as comet assay is an uncomplicated and sensitive technique for the detection of DNA damage at the level of the individual eukaryotic cell biology cell . It was first described by Singh et al. in 1988. It has since gained in popularity as a standard ... that cause the cells to lysis lyse . The lysis solution often used in the comet assay consists ... by Comet Assay Interest Group CaspLab http casplab.com CaspLab.com GPL software. http www.autocomet.com ... assay.php Trevigen, Inc. . Trevigen has developed a complete comet assay system which includes ... electrophoresis. Background The concept underlying the SCGE assay is that undamaged DNA retains ... resembles a comet hence comet assay with a circular head corresponding to the undamaged DNA that remains ... of damage. The comet assay is a versatile technique for detecting damage and with adjustments ... repair is taking place. The comet assay is an extremely sensitive DNA damage assay. This sensitivity ... s being researched is to be avoided. ref Theoretical and practical limitations to the assay are discussed e.g. in Klaude et al. 1996 and Collins et al. 1997 . ref The most common form of the assay is the alkaline version although there is as yet no definitive alkaline assay protocol. Due to its .... Applications Sperm DNA fragmentation A Comet assay can determine the degree of DNA fragmentation ..., Baruch 2002 Genotoxicity of the Kishon River, Israel the application of an in vitro cellular assay ... assay what can it really tell us? Mutation Research 375 2 183 193. small doi 10.1016 S0027 5107 ... assay mechanisms and technical considerations. Mutation Research 363 2 89 96. small doi 10.1016 0921 ... cell gel electrophoresis Comet assay. I. Management of invasive transitional cell human bladder ... 90265 0 small DEFAULTSORT Comet Assay Category Chemical tests Category Electrophoresis Category Molecular biology ar de Comet Assay fr Test des com tes it Test della cometa ru ... more details
Multiple issues context October 2009 orphan January 2007 The HELP Assay is an abbreviation for H paII tiny fragment E nrichment by L igation mediated Polymerase chain reaction P CR . ref name pmid16809668 It is one of several techniques used for determining whether DNA has been DNA methylation Assays to Detect DNA Methylation methylated . The technique can be adapted to examine DNA methylation within and around individual genes , or it can be expanded to examine methylation in an entire genome . The technique relies upon the properties of two restriction enzymes Hpa II and Msp I. The HELP assay ref name pmid16809668 cite journal author Khulan B, Thompson RF, Ye K, et al. title Comparative isoschizomer profiling of cytosine methylation The HELP assay journal Genome Research volume 16 issue 8 pages 1046 55 year 2006 month August pmid 16809668 pmc 1524864 doi 10.1101 gr.5273806 ref compares representations generated by Hpa II and by Msp I digestion of the genome followed by ligation mediated PCR. Hpa II only digests 5 C CG G 3 sites when the cytosine in the central CG dinucleotide is unmethylated, the Hpa II representation is enriched for the hypomethylated fraction of the genome. The Msp I representation is a control for copy number changes and PCR amplification difficulties. It was recently shown that cytosine methylation patterns tend to be concordant over short 1 kb regions. ref cite journal author Eckhardt F, Lewin J, Cortese R, et al. title DNA methylation profiling of human chromosomes 6, 20 and 22 journal Nature Genetics volume 38 issue 12 pages 1378 85 year 2006 month December pmid 17072317 doi 10.1038 ng1909 pmc 3082778 ref The patterns represented by the Hpa II sites therefore tend to be representative of other CG dinucleotides locally. The analysis of HELP data involves quality analysis and normalization. An analytical pipeline written in the R programming language ... HELP help.html The protocol for the HELP assay DEFAULTSORT Help Assay Category Microbiology ... more details
The ATPase assay is a membrane assay that indirectly measures the activity of ATP binding cassette transporters efflux transporters . ATP Binding Cassette or efflux transporters mediate the transport of substrates across cell membranes against a concentration gradient. ATP cleavage is tightly linked to substrate translocation, as the energy for the substrate translocation is derived from ATP hydrolysis . ATP hydrolysis yields inorganic phosphate Pi , which can be measured by a simple colorimetric reaction. The amount of Pi liberated is directly proportional to the activity of the transporter. ref cite journal author Glavinas H, M hn D, Jani M, Oosterhuis B, Her di Szab K, Krajcsi P title Utilization of membrane vesicle preparations to study drug ABC transporter interactions journal Expert Opinion on Drug Metabolism & Toxicology volume 4 issue 6 pages 721 32 year 2008 month June pmid 18611113 doi 10.1517 17425255.4.6.721 ref Use of ATPase Assay The ATPase assay is designed to indicate the nature of the interaction between the compound and the transporter. The ATPase assays are used in two different modes ATPase activation and ATPase inhibition. Transported substrates increase baseline ATPase activity, while inhibitors or slowly transported compounds inhibit baseline ATPase activity and or the ATPase activity measured in the presence of a stimulating agent. The ATPase assays can therefore have the potential for determining whether a compound acts as a transporter substrate and or inhibitor. ref cite journal author Kis E, Rajnai Z, Ioja E, et al. title Mouse Bsep ATPase assay a nonradioactive tool for assessment of the cholestatic potential of drugs journal Journal of Biomolecular Screening volume 14 issue 1 pages 10 5 year 2009 month January pmid 19029016 doi 10.1177 1087057108326145 ref ref cite journal author Sarkadi B, Price EM, Boucher RC, Germann UA, Scarborough GA title Expression of the human multidrug resistance cDNA in insect cells generates a high activity drug ... more details
Orphan date August 2011 A Nociception assay nocioception or nocioperception assay evaluates the ability ..., a researcher must be conscious as to which nociception assay to use. Formalin The formalin assay is the most popular chemical assays of nociception . It entails the injection of a Concentration ... as a result of inflammation . ref name multiple Typically, the formalin assay is used on rats however ... doi pdf 10.1201 9781420042566 c2 ref One major advantage of the formalin assay over ... name rd Additionally, as described before, this assay produces a response in two discrete stages, allowing .... The Von Frey assay, introduced by Maximilian von Frey and modified by Weinstein, uses Von Frey ... versus simply annoying, so this assay is a test of mechanical nociception or simply mechanical ... rd Tail Withdrawal Two versions of the tail withdrawal assay are commonly employed in pain sensitivity ... more variable both across and within subjects than those obtained from the tail withdrawal assay. Hot Plate File Hot plateassay.jpg thumb An example of a Hot Plate assay being performed on a mouse. A heat ... is measured. ref name multiple One complication of this assay is its unsuitability for repeated ... left An example of a traditional set up for the tail flick assay. The tail flick assay or tail flick ... and body weight . ref name multiple The most critical parameter for the tail flick assay is the beam ... 8.9.15. Print. ref Hargreaves The Hargreaves assay uses a high intensity beam of light directed ... to withdraw its hindpaw . ref name multiple In contrast to the tail flick assay, rodents .... Cut off latency for the Hargreaves assay is commonly set at 10 seconds . ref name assay Varnado Rhodes ... flick assay is that it allows independent assessment of treatment effects on both sides of the body ... receptor NAChR ligands in the rat tail flick assay http www.sciencedirect.com science? ob ArticleURL ... noxious stimulation releases spinal PGE2 during the first phase in the formalin assay of the rat ... more details
assay, the modified nucleotide must not only be an acceptable substrate for TdT, but the detection ... references External links MeshName TUNEL DEFAULTSORT Tunel Assay Category Programmed cell ... more details
The term dilution assay is generally used to designate a special type of bioassay in which one or more preparations e.g. a drug are administered to experimental units at different dose levels inducing a measurable biological response. The dose levels are prepared by dilution in a diluent that is inert in respect of the response. The experimental units can for example be cell cultures, tissues, organs or living animals. The biological response may be quantal e.g. positive negative or quantitative e.g. growth . The goal is to relate the response to the dose, usually by interpolation techniques, and in many cases to express the potency activity of the test preparation s relative to a standard of known potency activity. Dilution assays can be direct or indirect. In a direct dilution assay the amount of dose needed to produce a specific fixed response is measured, so that the dose is a stochastic variable defining the tolerance distribution . Conversely, in an indirect dilution assay the dose levels are administered at fixed dose levels, so that the response is a stochastic variable. Statistical models For a mathematical definition of a dilution assay an observation space math U math is defined and a function math f U rightarrow mathbb R math so that the responses math u in U math are mapped to the set of real numbers. It is now assumed that a function math F math exists which relates the dose math z in 0, infty math to the response math f u F z e math in which math e math is an error term with expectation 0. math F math is usually assumed to be continuous function continuous and monotone function monotone . In situations where a standard preparation is included it is furthermore ... e math follows a binomial distribution . Example Microbiological assay of antibiotics image DilutionAssay.png Parallel line assay An antibiotic standard shown in red and test preparation shown in blue ... Assay, 3rd Ed. Griffin, London. ISBN 0 02 844640 2 Govindarajulu, Z. 2001 . Statistical Techniques ... more details
Image DU640 spectrophotometer.jpg thumb right 250px Beckman DU640 UV Vis spectrophotometer. Enzyme assay s are laboratory methods for measuring enzyme enzymatic activity. They are vital for the study of enzyme kinetics and enzyme inhibitor enzyme inhibition . Enzyme units Amounts of enzymes can either ... sample will have a lower specific activity, allowing purity to be calculated. Types of assay ... can be split into two groups according to their sampling method continuous assays , where the assay ... assays are most convenient, with one assay giving the rate of reaction with no further work necessary ... in how much light the assay solution absorbs. If this light is in the visible region you can actually see a change in the color of the assay, these are called colorimetric assays . The MTT assay , a redox assay using a tetrazolium dye as substrate is an example of a colorimetric assay. UV light is often ... thumb 350px right Coupled assay for hexokinase using glucose 6 phosphate dehydrogenase . Even ... to use a spectrophotometric assay for the enzyme by using a coupled assay . Here, the product ... 1 shows the coupled assay for the enzyme hexokinase , which can be assayed by coupling its production ... to measure reactions that are impossible to assay in any other way. ref cite journal author Todd MJ, Gomez J title Enzyme kinetics determined using calorimetry a general assay for enzyme activity ... produce light and this can be measured to detect product formation. These types of assay can be extremely ... be increased by labelling the substrates products with a radioactive or fluorescent tag. Assay sensitivity ... were to use an assay measuring activity for one second, it would give high activity at high temperatures, however if you were to use an assay measuring product formation over an hour, it would give ... of enzyme assays MTT assay Overlay assay Fluorescein diacetate hydrolysis See also Restriction enzyme DNase footprinting assay Enzyme kinetics References references External links http openwetware.org ... more details
Image MTT Plate.jpg thumb 200px A microtiter plate after an MTT assay. Increasing amounts of cells resulted in increased purple colouring. The MTT assay and the MTS assay are Colorimetry chemical method colorimetric assay s for measuring the activity of enzymes that reduce MTT or close dyes XTT, MTS, WSTs to formazan dyes, giving a purple color. A main application allows to assess the viability cell counting and the proliferation of Cell biology cells cell culture assays . It can also be used to determine cytotoxicity of potential medicinal agents and toxic materials, since those agents would stimulate or inhibit cell viability and growth. MTT and related tetrazolium salts Image Mttscheme.png MTT reduction scheme right MTT 3 4,5 di Di methyl thiazole thiazol 2 yl 2,5 di phenyl nowiki tetrazolium nowiki bromide, a yellow tetrazole , is reduced to purple formazan in living cells. ref name pmid6606682 cite journal author Mosmann, Tim year 1983 month December title Rapid colorimetric assay for cellular growth and survival application to proliferation and cytotoxicity assays journal Journal Of Immunological Methods volume 65 issue 1 2 pages 55 63 issn 0022 1759 doi 10.1016 0022 1759 83 90303 4 pmid 6606682 url http linkinghub.elsevier.com retrieve pii 0022 1759 83 90303 4 ref A solubilization solution usually either dimethyl sulfoxide , an acidified ethanol solution, or a solution of the detergent sodium dodecyl sulfate in diluted hydrochloric acid is added to dissolve the insoluble purple formazan product into a colored solution. The absorbance of this colored solution can be quantified by measuring at a certain wavelength usually between 500 and 600 nm by a spectrophotometer . The absorption maximum is dependent on the solvent employed. XTT 2,3 bis 2 methoxy 4 nitro 5 ... JA, Cory JG year 1991 month July title Use of an aqueous soluble tetrazolium formazan assay ... cyto.10080 See also Tetrazolium chloride Formazan DEFAULTSORT Mtt Assay Category Biochemistry methods ... more details
A clonogenic assay is a microbiology technique for studying the effectiveness of specific agents on the survival and proliferation of cells. It is frequently used in oncology cancer research laboratories to determine the effect of drugs or radiation on proliferating tumor cells ref cite journal last1 Hoffman first1 Robert M. title In vitro sensitivity assays in cancer A review, analysis, and prognosis journal Journal of Clinical Laboratory Analysis volume 5 issue 2 pages 133 43 year 1991 pmid 2023059 doi 10.1002 jcla.1860050211 ref as well as for titration of Cell killing Particles CKPs in virus stocks. ref cite journal last1 Ngunjiri first1 J. M. last2 Sekellick first2 M. J. last3 Marcus first3 P. I. title Clonogenic Assay of Type a Influenza Viruses Reveals Noninfectious Cell Killing Apoptosis Inducing Particles journal Journal of Virology volume 82 issue 6 pages 2673 80 year 2008 pmid 18184709 pmc 2258965 doi 10.1128 JVI.02221 07 ref Although this technique can provide accurate results, the assay is time consuming to set up and analyse and can only provide data on tumor cells that can grow in culture. The word clonogenic refers to the fact that these cells are clone genetics clone s of one another. Procedure The experiment involves three major steps The treatment is applied to a sample of cells. The cells are plated in a tissue culture vessel and allowed to grow. The colonies produced are fixed, stained, and counted. At the conclusion of the experiment, the percentage of cells that survived the treatment is measured. A graphical representation of survival versus drug concentration or dose of ionizing radiation is called a cell survival curve . ref cite journal last1 Franken ... last5 Van Bree first5 Chris title Clonogenic assay of cells in vitro journal Nature Protocols volume ... last1 Hamburger first1 Anne W. title The Human Tumor Clonogenic Assay as a Model System in Cell Biology ... Microbiology Cancer References reflist DEFAULTSORT Clonogenic Assay Category Microbiology techniques ... more details
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