• analyte
  • In one embodiment a test sample suspected of containing the analyte of interest may be contacted with the capture reagent to form a charged capture reagent/analyte complex. (google.ca)
  • The complex is then contacted to the oppositely charged solid phase to attract, attach, and immobilize the capture reagent/analyte complex. (google.ca)
  • and d) detecting said indicator reagent associated with said solid phase to determine the presence or amount of the analyte in the test sample. (google.ca)
  • 7. The method according to Claim 1 , further comprising the addition of an ancillary specific binding member, wherein said ancillary specific binding member is capable of binding the analyte and is capable of binding a member selected from the group consisting of said indicator reagent or said capture reagent in an indirect assay. (google.ca)
  • A typical titration begins with a beaker or Erlenmeyer flask containing a very precise volume of the analyte and a small amount of indicator (such as phenolphthalein) placed underneath a calibrated burette or chemistry pipetting syringe containing the titrant. (wikipedia.org)
  • Small volumes of the titrant are then added to the analyte and indicator until the indicator changes color in reaction to the titrant saturation threshold, reflecting arrival at the endpoint of the titration. (wikipedia.org)
  • substance
  • This invention presents novel assay methods employing a capture reagent, involving a first binding member typically conjugated to a polymeric anion substance, and a solid phase material containing a reaction site comprising a polymeric cation substance having a nitrogen content of at least about two. (google.ca)
  • The use of a polycationic substance, having a nitrogen content of at least about two percent (excluding the counter ions), to prepare a suitably charged solid phase provides a solid phase that can be subjected to a greater extent of manipulation, such as multiple washes, without losing the capability to attract and retain the capture reagent. (google.ca)
  • react
  • RMg+ RMg+ + X− → RMgX A limitation of Grignard reagents is that they do not readily react with alkyl halides via an SN2 mechanism. (wikipedia.org)
  • Drops
  • Drops of safe reagent are then placed into the wells in sequence, which first bind with the cholesterol in the skin and then subsequently change color in proportion to the amount of bound cholesterol present. (issuu.com)
  • Depending on the endpoint desired, single drops or less than a single drop of the titrant can make the difference between a permanent and temporary change in the indicator. (wikipedia.org)
  • After colonies have grown on the medium, 2-3 drops of the reagent DMPD are added to the surface of each organism to be tested. (wikipedia.org)
  • reactions
  • While pH indicators work efficiently at their designated pH range, they are usually destroyed at the extreme ends of the pH scale due to undesired side reactions. (wikipedia.org)
  • Grignard reactions and reagents were discovered by and are named after the French chemist François Auguste Victor Grignard (University of Nancy, France), who published it in 1900 and was awarded the 1912 Nobel Prize in Chemistry for this work. (wikipedia.org)
  • Similar pathways are assumed for other reactions of Grignard reagents, e.g., in the formation of carbon-phosphorus, carbon-tin, carbon-silicon, carbon-boron and other carbon-heteroatom bonds. (wikipedia.org)
  • On the other hand, they readily participate in transmetalation reactions: RMgX + AlX → AlR + MgX2 For this purpose, commercially available Grignard reagents are especially useful because this route avoids the problem with initiation. (wikipedia.org)
  • In reactions involving Grignard reagents, it is important to exclude water and air, which rapidly destroy the reagent by protonolysis or oxidation. (wikipedia.org)
  • zones
  • Process for the production of a test devices using extruder casting machines or cascade casting machines is disclosed in which reagent zones are produced on a common surface with remaining portion of test device such that reagent zone is protected by being in the same plane as a portion of the test device. (google.com)
  • weak
  • In and of themselves, pH indicators are frequently weak acids or weak bases. (wikipedia.org)
  • pH indicators that are weak protolytes, the Henderson-Hasselbalch equation for them can be written as: pH = pKa + log10 [Ind− ] / [HInd] The equation, derived from the acidity constant, states that when pH equals the pKa value of the indicator, both species are present in a 1:1 ratio. (wikipedia.org)
  • If one reagent is a weak acid or base and the other is a strong acid or base, the titration curve is irregular and the pH shifts less with small additions of titrant near the equivalence point. (wikipedia.org)
  • detection
  • The Renz and Loew reagent, which uses p-dimethylaminocinnamaldehyde and may also be used for the detection of flavonoids. (wikipedia.org)
  • The van URK-Salkowski reagent - a sensitive and specific chromogenic reagent for silica gel thin-layer chromatographic detection and identification of indole derivatives" (PDF). (wikipedia.org)
  • form
  • The invention preferably relates to a process for the production of test strips in which the reagent zone and the test strip holder form a plane, planar carrier film. (google.com)
  • Grignard reagents are similar to organolithium reagents because both are strong nucleophiles that can form new carbon-carbon bonds. (wikipedia.org)
  • The Ehrlich reagent works by binding to the C2 position of two indole moieties to form a resonance stabilised carbenium ion compound. (wikipedia.org)
  • the hydride reagent reacts with water to form solid calcium hydroxide, while it is also a strong enough base to generate the trityl anion. (wikipedia.org)
  • color
  • Normally, the indicator causes the color of the solution to change depending on the pH. (wikipedia.org)
  • Because of the subjective choice (determination) of color, pH indicators are susceptible to imprecise readings. (wikipedia.org)
  • Sometimes, a blend of different indicators is used to achieve several smooth color changes over a wide range of pH values. (wikipedia.org)
  • The figure on the right shows indicators with their operation range and color changes. (wikipedia.org)
  • As an acid-base indicator, it changes color from yellow to red between pH 12 and pH 13. (wikipedia.org)
  • Color Test Reagents/Kits for Preliminary Identification of Drugs of Abuse" (PDF). (wikipedia.org)
  • The reagent is a dark-blue to maroon color when oxidized, and colorless when reduced. (wikipedia.org)
  • During incubation, metabolism produces color changes that are either spontaneous or revealed by the addition of reagents. (wikipedia.org)
  • For example, when carbohydrates are fermented, the pH within the well decreases and that change is indicated by a change in the color of the pH indicator. (wikipedia.org)
  • Temperature
  • The transition range may shift slightly depending on the concentration of the indicator in the solution and on the temperature at which it is used. (wikipedia.org)
  • change
  • The hydrophilic group on the ammonia salts also change the dissociation of the reagent to be used with bromopyrogallol red to a more acidic region. (wikipedia.org)
  • for example, olfactory indicators show change in their odor. (wikipedia.org)
  • known
  • The principle can be illustrated by taking the indicator to be a simple acid, HA, which dissociates into H+ and A−. HA ⇌ H+ + A− The value of the acid dissociation constant, pKa, must be known. (wikipedia.org)
  • uses
  • The "improved hallucinogen reagent", which uses 5% DMAB in 1:1 concentrated phosphoric acid (specific gravity 1.75) / methanol mixture. (wikipedia.org)
  • addition
  • The addition of the Grignard reagent to the carbonyl typically proceeds through a six-membered ring transition state. (wikipedia.org)
  • presence
  • The reagent will also give a positive result for opium, despite the opiates not containing the indole functional group, because of the presence of tryptophan in natural opium. (wikipedia.org)
  • group
  • The Grignard reagent functions as a nucleophile, attacking the electrophilic carbon atom that is present within the polar bond of a carbonyl group. (wikipedia.org)
  • blue
  • By reacting the bromopyrogallol red with niobium(V) in a tartrate medium at pH 6.0, an intense blue coloured 3:1 reagent was formed. (wikipedia.org)
  • System
  • With the HRP-H2O2-BPR catalytic system, the bromopyrogallol red is determined to be an efficient reagent and quantitation of HRP can be performed. (wikipedia.org)