ELISA and Direct ELISA Technique

qualitative analysis of macromolecules

to avoid non-specific adsorption of other proteins

the signal decreases

<p>competitive reaction between targets and enzyme-labeled targets</p> Signup and view all the answers

<p>Belanger</p> Signup and view all the answers

<p>Increased sensitivity and versatility</p> Signup and view all the answers

<p>It binds to the antigen in the sample</p> Signup and view all the answers

<p>Hapten can be exposed on the surface of the microtiter plate</p> Signup and view all the answers

<p>The signal increases</p> Signup and view all the answers

<p>The use of two antibodies that recognize different epitopes</p> Signup and view all the answers

<p>The resultant hapten–enzyme conjugates are not recognized by the immobilized antibody, leading to failure of the analysis.</p> Signup and view all the answers

<p>The two-binding process of the primary antibody and enzyme-labeled secondary antibody.</p> Signup and view all the answers

<p>Higher specificity due to the use of two antibodies possessing different epitopes.</p> Signup and view all the answers

<p>Competitive ELISA involves direct competition between the antibody in the sample and enzyme-labeled antibody, whereas indirect competitive ELISA involves the combination of indirect ELISA and competitive ELISA.</p> Signup and view all the answers

<p>The labeling step, which may lead to inactivation of the antibody.</p> Signup and view all the answers

<p>The sodium periodate (NaIO4) oxidation method</p> Signup and view all the answers

<p>The Mannich reaction</p> Signup and view all the answers

<p>Via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF–MS) using sinapinic acid as the matrix</p> Signup and view all the answers

<p>Into two groups: 20(S)-protopanaxadiol and 20(S)-protopanaxatriol</p> Signup and view all the answers

<p>To recognize a bioactive skeleton or a group of bioactive compounds</p> Signup and view all the answers

<p>It is an expensive and labor-intensive process.</p> Signup and view all the answers

<p>To immobilize the VL region conjugated with biotin.</p> Signup and view all the answers

<p>MAb exhibits higher specificity than PAb.</p> Signup and view all the answers

<p>Because they are low molecular weight compounds (haptens) with immense structural diversity.</p> Signup and view all the answers

<p>It is a factor of specificity calculated by the ratio of IC50 for the target antigen to that for the test compounds.</p> Signup and view all the answers

<p>Both macromolecules and hapten can be detected when hapten is exposed on the surface of the microtiter plate.</p> Signup and view all the answers

<p>The signal increases</p> Signup and view all the answers

<p>Higher specificity</p> Signup and view all the answers

<p>Failure of the analysis</p> Signup and view all the answers

<p>The labeling step</p> Signup and view all the answers

<p>In direct ELISA, the signal increases with an increasing amount of target, whereas in competitive ELISA, the signal decreases with an increasing amount of target.</p> Signup and view all the answers

<p>To detect the immobilized target and produce a color signal with an appropriate substrate.</p> Signup and view all the answers

<p>Qualitative analysis of macromolecules.</p> Signup and view all the answers

<p>It binds to the target antigen in the sample and the enzyme-labeled antigen.</p> Signup and view all the answers

<p>Because a labeling enzyme is required to measure the antigen.</p> Signup and view all the answers

<p>To allow competition between the immobilized antigen and free antigen against antibodies.</p> Signup and view all the answers

<p>It recognizes different epitopes of the primary antibody, leading to increased sensitivity.</p> Signup and view all the answers

<p>To anchor the target antigen, enabling its detection.</p> Signup and view all the answers

<p>Sandwich ELISA is generally suitable for measuring macromolecules, with some exceptions.</p> Signup and view all the answers

<p>It is commercially available, leading to high versatility.</p> Signup and view all the answers

<p>The advantage of using recombinant antibodies in ELISA is that they can be produced with specific characteristics and can be applied to various ELISA types.</p> Signup and view all the answers

<p>The VL region is conjugated with biotin and allowed to react with streptavidin to immobilize the VL region.</p> Signup and view all the answers

<p>MAb recognizes only one epitope, while PAb recognizes several epitopes, making MAb more specific.</p> Signup and view all the answers

<p>The NaIO4 oxidation method is used to prepare hapten-carrier protein conjugates for glycosides, which involves the oxidative cleavage of vicinal 1,2-diols of the sugar moieties to form imides with the amino group of lysine residues in the carrier proteins.</p> Signup and view all the answers

<p>OS-ELISA is more easy and effective than traditional sandwich ELISA, which requires immobilization of the capture antibody and is more labor-intensive and expensive.</p> Signup and view all the answers

<p>They act as a useful and effective tool for recognizing a bioactive skeleton or a group of bioactive compounds by simultaneous determination.</p> Signup and view all the answers

<p>High antibody titers with moderate antibody specificity are induced from 15–30 hapten molecules per carrier protein, while a lower number of hapten molecules exhibits a slower immune response with higher specificity.</p> Signup and view all the answers

<p>It is an important reaction for obtaining specific anti-hapten antibodies, as it leads to the production of highly specific MAb.</p> Signup and view all the answers

<p>They are classified into two groups according to their structure: 20(S)-protopanaxadiol and 20(S)-protopanaxatriol.</p> Signup and view all the answers

<p>MAb exhibit extremely high specificity to targets with high sensitivity, even with a low number of hapten molecules bound to carrier proteins.</p> Signup and view all the answers

<p>An antigen or an antibody is immobilized on the surface of a microtiter plate.</p> Signup and view all the answers

<p>It competes with the target antigen in the sample for binding to the immobilized antibody.</p> Signup and view all the answers

<p>In direct ELISA, the signal intensity increases with an increasing amount of target antigen, whereas in competitive ELISA, the signal intensity decreases with an increasing amount of target antigen.</p> Signup and view all the answers

<p>To develop color with an appropriate substrate, allowing for the detection of the target antigen or antibody.</p> Signup and view all the answers

<p>Because it can detect the presence of macromolecules, but not quantify them.</p> Signup and view all the answers

<p>It can only measure macromolecules because it requires a labeling enzyme to measure the antigen.</p> Signup and view all the answers

<p>It is the base style for other types of ELISA.</p> Signup and view all the answers

<p>Measuring macromolecules.</p> Signup and view all the answers

<p>The resultant hapten-enzyme conjugates are not recognized by the immobilized antibody, leading to failure of the analysis.</p> Signup and view all the answers

<p>The competition between the antibody in the sample and enzyme-labeled antibody is observed.</p> Signup and view all the answers

<p>Higher specificity and versatility</p> Signup and view all the answers

<p>To bind to the immobilized antigen</p> Signup and view all the answers

<p>To develop color with substrate</p> Signup and view all the answers

<p>Indirect ELISA measures the presence of antibody, while indirect competitive ELISA measures the presence of both antibody and antigen.</p> Signup and view all the answers

<p>It may not be suitable for detecting hapten due to the requirement of two antibodies.</p> Signup and view all the answers

<p>The signal decreases</p> Signup and view all the answers

<p>Higher sensitivity and versatility</p> Signup and view all the answers

<p>To bind to the immobilized antigen and compete with the antibody in the sample</p> Signup and view all the answers

<p>The role of the enzyme-labeled secondary antibody is to detect the primary antibody that binds to the immobilized antigen.</p> Signup and view all the answers

<p>The main advantage of using indirect ELISA methods is their sensitivity and versatility.</p> Signup and view all the answers

<p>The purpose of the capture antibody is to bind to the target antigen.</p> Signup and view all the answers

<p>The signal decreases with increasing amount of free antigen.</p> Signup and view all the answers

<p>The purpose is to form a sandwich system, allowing for the specific detection of the target antigen.</p> Signup and view all the answers

<p>Polyclonal antibodies recognize different epitopes of the primary antibody, leading to increased sensitivity.</p> Signup and view all the answers

<p>The main difference is the direction of the signal change in response to increasing amount of antigen.</p> Signup and view all the answers

<p>The advantage is that it can be used if the original animal species of the primary antibody are unified.</p> Signup and view all the answers

<p>The limitation is that the cross-reaction of the secondary antibody should be considered.</p> Signup and view all the answers

<p>The significance is that it allows for a highly specific assay.</p> Signup and view all the answers

<p>It is an expensive and labor-intensive process.</p> Signup and view all the answers

<p>To form a ternary complex with the VL region and antigen.</p> Signup and view all the answers

<p>They enable the production of unique and interesting immunoassays based on the interaction of variable regions of heavy and light chains.</p> Signup and view all the answers

<p>MAb tends to exhibit higher specificity because it recognizes only one epitope.</p> Signup and view all the answers

<p>To immobilize the VL region conjugated with biotin.</p> Signup and view all the answers

<p>Because plant secondary metabolites are typically low molecular weight compounds with immense structural diversity.</p> Signup and view all the answers

<p>It is a factor of specificity calculated by the ratio of IC50 for the target hapten to that for the test compounds.</p> Signup and view all the answers

<p>It considerably affects the specificity of the resultant antibody.</p> Signup and view all the answers

<p>They can be applied to ELISA, although the corresponding secondary antibodies need to be prepared.</p> Signup and view all the answers

<p>It is incubated with the antigen to form a ternary complex with the VL region.</p> Signup and view all the answers

<p>The Mannich reaction is important for obtaining specific antibodies to haptens. It allows for the production of highly specific MAb to haptens, such as DZ, and exhibits higher specificity than the NaIO4 oxidation method.</p> Signup and view all the answers

<p>The number of hapten molecules bound to carrier proteins affects the specificity of antibodies. High antibody titers with moderate antibody specificity are induced from 15-30 hapten molecules per carrier protein, while a lower number of hapten molecules exhibits a slower immune response with higher specificity.</p> Signup and view all the answers

<p>Antibodies with broad cross-reactivity can be used as a useful and effective tool for recognizing a bioactive skeleton or a group of bioactive compounds, enabling the simultaneous determination of the total compounds in plant samples.</p> Signup and view all the answers

<p>Cross-reactivity (CR) is significant in evaluating the specificity of antibodies against haptens. Antibodies with broad CR tend to exhibit lower specificity, while those with lower CR exhibit higher specificity.</p> Signup and view all the answers

<p>Ginsenosides are classified into two groups according to their structure: 20(S)-protopanaxadiol and 20(S)-protopanaxatriol.</p> Signup and view all the answers

<p>MAbs against specific ginsenosides in icELISA enable the specific determination of the target compounds, allowing for the simultaneous determination of the total ginsenosides in plant samples.</p> Signup and view all the answers

<p>The NaIO4 oxidation method is used to prepare hapten-carrier protein conjugates, but it tends to exhibit broad CR, especially with compounds containing similar aglycone parts.</p> Signup and view all the answers

<p>Antibodies in icELISA enable the simultaneous determination of the total compounds in plant samples, making it a useful tool for the analysis of plant secondary metabolites.</p> Signup and view all the answers

<p>The hapten-carrier protein conjugates are significant in antibody production as they determine the specificity of the resultant antibodies.</p> Signup and view all the answers

<p>Specific antibodies in icELISA enable the specific determination of the target compounds, allowing for the accurate analysis of plant secondary metabolites.</p> Signup and view all the answers