In chemical analysis, the process of determining proportions of metal, particularly precious metal, in ores and metallurgical products. The most important assaying technique grew largely out of the experiments of the ancient alchemists and goldsmiths. Precious metals tend to occur as scattered particles randomly distributed, so a large sample of ore is required. Such large samples (typically containing gold, silver, and lead) are still most economically assayed by this ancient method, which involves several steps of heating and cooling. More sophisticated recent methods, such as spectrochemical analysis, are not suited to assaying precious metal ores because the samples of the inhomogeneous ore that must be used are larger than the instruments can handle. See also parting
In general, the qualitative or quantitative analysis of a substance In MGI, an assay is a type of experiment that is designed to detect the level of gene expression of a particular gene, or to determine the pattern of expression of a gene among different tissue types, anatomical structures, or developmental stages The assay may detect one or more of the RNA transcripts of a gene or one or more of its protein products Assay types in MGI include: Immunohistochemistry Northern blot Protein histochemistryRNA In situ hybridization RNAse protection RT-PCR Western blot
a test, especially one used to detect the presence and/or concentration of a component, drug, or microorganism in the blood or other body fluids or tissues
A method to analyze or quantify a substance in a sample An assay is an analysis done to determine: 1 The presence of a substance and the amount of that substance 2 The biological or pharmacological potency of a drug
The analysis of a substance or mixture to determine its constituents or their level In Life Sciences, it is also the estimation of strength of a drug or substance by comparing its effects in test animals to a reference standard
make an effort or attempt; "He tried to shake off his fears"; "The infant had essayed a few wobbly steps"; "The police attempted to stop the thief"; "He sought to improve himself"; "She always seeks to do good in the world"
an instrument, kit or test system which applies one or more technical procedures or one or more analytical methods, using a defined and characterized protocol, to determine, measure or otherwise describe the presence or absence of an analyte
the process of establishing the standards of purity of gold, silver and other alloys reach the required legal standard without actually analysing the total composition of the alloy After successful assay the article is hallmarked outside the US dvb regularly assays its finished pieces to ensure standards are maintained though it is not a legal requirement in the US
An assay is a test of a substance to find out what chemicals it contains. It is usually carried out to find out how pure a substance is. to test a substance, especially a metal, to see how pure it is or what it is made of (assaier, essaier, from exagium; ESSAY)
an appraisal of the state of affairs; "they made an assay of the contents"; "a check on its dependability under stress" a written report of the results of an analysis of the composition of some substance a substance that is undergoing an analysis of its components analyze (chemical substances)
a quantitative or qualitative test of a substance (especially an ore or a drug) to determine its components; frequently used to test for the presence or concentration of infectious agents or antibodies etc
A set of operations having the object of determining the value of a quantity In analytical chemistry, this term is synonymous with measurement [IUPAC Compendium]
Analysis of a substance, or of components in a mixture, or of the biological, chemical, or pharmacological potency of a drug Forms of assay include: Endpoint assay a single measurement is made at a fixed time Kinetic assay increasing amounts of a product are formed with time, and are monitored at multiple points Microbiological assay measurement of the concentration of antimicrobials in biological material Immunological assay analysis or measurement is based on antigen-antibody reactions
1 The quantitative or qualitative evaluation of a hazardous substance in water, food, soil, and air 2 The results of such an evaluation See also bioassay
a written report of the results of an analysis of the composition of some substance a substance that is undergoing an analysis of its components analyze (chemical substances)
The act or process of ascertaining the proportion of a particular metal in an ore or alloy; especially, the determination of the proportion of gold or silver in bullion or coin
An assay is a test of the purity of an alloy A tiny piece of metal is scraped from the piece and the percentage of gold or silver is determined Official assay offices determine whether a piece qualifies for an appropriate hallmark
To subject, as an ore, alloy, or other metallic compound, to chemical or metallurgical examination, in order to determine the amount of a particular metal contained in it, or to ascertain its composition