assay

1. 1. Qualitative or quantitative analysis of a metal or ore to determine its components.
   2. A substance to be so analyzed.
   3. The result of such an analysis.
2. An analysis or examination.
3. A bioassay.
4. Archaic. An attempt; an essay.

1. 1. To subject (a metal, for example) to chemical analysis so as to determine the strength or quality of its components.
   2. To bioassay.
2. To examine by trial or experiment; put to a test: assay one's ability to speak Chinese.
3. To evaluate; assess: assayed the situation before taking action. See synonyms at estimate.
4. To attempt; try.

To be shown by analysis to contain a certain proportion of usually precious metal.

[Middle English, from Old French essai, assai. See essay.]

The act of testing the purity of precious metals.

Investopedia Says:
In futures contracts where the underlying commodities are precious metals, the quality must be assayed to ensure that they are of basis grade.

Related Links:
For those who are new to futures but want a solid understanding of them, this tutorial explains what futures contracts are, how they work and why investors use them. Futures Fundamentals

Test of a metal's purity to verify that it meets the standards for trading on a commodities exchange. For instance, a 100 troy-ounce bar of refined gold must be assayed at a fineness of not less than 995 before the Comex will allow it to be used in settlement of a gold contract.

noun

1. A procedure that ascertains effectiveness, value, proper function, or other quality: essay, proof, test, trial, tryout. See investigate.
2. A trying to do or make something: attempt, crack, effort, endeavor, essay, go, offer, stab, trial, try. Informal shot. Slang take. See try.

verb

1. To subject to a procedure that ascertains effectiveness, value, proper function, or other quality: check, essay, examine, prove, test, try, try out. Idioms: bring to the test, make trial of, put to theprooftest. See investigate.
2. To make a judgment as to the worth or value of: appraise, assess, calculate, estimate, evaluate, gauge, judge, rate, size up, valuate, value. Idioms: take the measure of. See value/worthlessness/evaluation.
3. To make an attempt to do or make: attempt, endeavor, essay, seek, strive, try. Idioms: have a go at, havemaketakea shot at, havetakea whack at, make a stab at, take a crack at. See try.

For more information on assaying, visit Britannica.com.

Determination of the purity of a substance or the amount or activity of any particular constituent of a mixture.

• biological a. — bioassay; determination of the potency of a drug or other substance by comparing the effects it has in a biological system with those of a reference standard.

Tutor's tip: An "assay" (examination of characteristics) following a blood test can help diagnose a disease, but can't help you with the "essay" (analytic or interpretive written composition) portion of your English test!

This article is about the the analysis and testing of the properties of a biochemical substance. For the analysis of metals, see metallurgical assay. For the commune in the Indre-et-Loire, see Assay, Indre-et-Loire.

Look up assay in Wiktionary, the free dictionary.

An assay is a procedure in molecular biology for testing and/or measuring the activity of a drug or biochemical in an organism or organic sample.^[1][2] A quantitative assay may also measure the amount of a substance in a sample. Bioassays and immunoassays are among the many varieties of specialized biochemical assays. Other assays measure such processes as enzyme activity, antigen capture, stem cell activity, and competitive protein binding.

Contents 1 Assay varieties 1.1 Cytotoxicity 1.2 DNA 1.3 Protein 1.4 RNA 1.5 Cell counting 1.6 Petrochemistry 1.7 Virology 1.8 Cellular secretions 1.9 Drugs 2 See also 3 Notes

Assay varieties

This section does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. (May 2009)

Cytotoxicity

A cytotoxicity assay measures how toxic a chemical compound is to cells.

• MTT assay
• SRB (Sulforhodamine B) assay

DNA

Assays for studying interactions 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
• Secretion assay

RNA

• Nuclear run-on

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]] count.

• CASY cell counting technology
• Coulter counter

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.

One may use a viral plaque assay to calculate the number of viruses 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 or cytokine) can be detected using the ELISA technique. The number of cells which secrete those particular substances can be determined using a related technique, the ELISPOT assay.

Drugs

• Illegal drug testing
• Radioligand binding assay

See also

• Analytical chemistry
• CASY cell counting technology
• ELISA
• MELISA
• Multiplex (assay)
• Pharmaceutical chemistry
• Titration

Notes

1. ^ The American Heritage Dictionary of the English Language. Fourth Edition. Houghton Mifflin Company: 2000.
2. ^ McKean, Erin (ed.). The New Oxford American Dictionary. Second edition. Oxford University Press: 2005.

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)

Dansk (Danish)
n. - probering, finhedsanalyse
v. tr. - probere, finhedsbestemme
v. intr. - probere, finhedsbestemme

Nederlands (Dutch)
het analyseren van metaal/erts, analyseerbaar materiaal, metaal/erts analyseren, goud-/zilvergehalte toetsen, pogen

Français (French)
n. - essai
v. tr. - essayer (du minerai), essayer, tenter de (arch)
v. intr. - être analysé, contenir de l'or

Deutsch (German)
n. - Probe, Analyse
v. - prüfen, analysieren

Ελληνική (Greek)
v. - δοκιμάζω, καρατάρω ή αναλύω (πολύτιμο) μέταλλο
n. - δοκιμασία, τεστ, έλεγχος καθαρότητας μετάλλου

Italiano (Italian)
esaminare

Português (Portuguese)
v. - ensaiar, testar, analisar
n. - ensaio (m), teste (m), análise (f)

Русский (Russian)
производить количественный анализ, пробовать, пытаться, испытание

Español (Spanish)
n. - prueba, ensayo
v. tr. - probar, ensayar
v. intr. - someter a prueba, probarse

Svenska (Swedish)
v. - pröva, analysera
n. - prövning, justering

中文（简体）(Chinese (Simplified))
化验, 分析, 尝试, 被验明成分

中文（繁體）(Chinese (Traditional))
n. - 化驗, 分析
v. tr. - 嘗試, 化驗, 分析
v. intr. - 被驗明成分

한국어 (Korean)
n. - 분석 시험, 시험
v. tr. - 을 분석하다, 을 시험하다, 을 평가하다
v. intr. - 금속을 함유하다

日本語 (Japanese)
v. - 分析する
n. - 分析試験, 試金

العربيه (Arabic)
‏(فعل) يجرب, يختبر, يفحص, يحلل (الاسم) اختبار, فحص, تحليل‏

עברית (Hebrew)
n. - ‮בחינת המרכיבים, האיכות והריכוז של מתכת או חומר-גלם‬
v. tr. - ‮בדק, בחן, קבע את הריכוז של‬
v. intr. - ‮הכיל שיעור מסוים של מתכת יקרה‬

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