A mutation is a change in a DNA sequence that can be caused by errors during DNA replication, exposure to mutagens like radiation or chemicals, or infection by viruses. Mutations can be passed on to offspring or occur somatically in body cells. Some mutations can cause genetic disorders like sickle cell anemia, Down syndrome, or Edwards syndrome, while others may have no effect or even provide an advantage to survival. Mutants arise from mutations in existing genomes due to errors in DNA replication or repair.
Les principales techniques sont les réactions de précipitation, les réactions d'agglutination et les réactions de neutralisation.
La plupart de ces techniques utilisent les propriétés des anticorps monoclonaux.
Leur affinité et leur spécificité de liaison à leur cible fait d'eux des outils incontournables de détection.
Ils permettent de déterminer la présence d'un épitope particulier dans un échantillon, permettant ainsi dans les techniques comme le western blot ou l'ELISA de détecter des protéines, ou des modifications particulières de protéine (phosphorylation, acétylation, etc.).
Biotechnology is the use of living organisms to develop useful products. Modern biotechnology techniques include isolating DNA, inserting genes into vectors, and transforming host cells. Applications include producing Bt crops for pest resistance, producing vaccines and diagnosing diseases. New advances include artificial lymph nodes, non-invasive cancer detection from saliva, smart contact lenses to monitor eye pressure, and machines that can scan the liver non-invasively. Biotechnology continues to progress rapidly with applications in agriculture, medicine, and other fields.
This document provides an overview of protein therapeutics. It discusses how mutations or abnormalities in any of the estimated 25,000-40,000 human genes can result in disease. Protein therapeutics aim to alleviate such diseases. The timeline shows key developments in protein therapeutics from 1953 to present. Therapeutic proteins are classified and the challenges of delivering them are discussed. A case study examines efforts to achieve a cure for HIV infection through complete virus suppression while minimizing toxicity. Further work is needed to optimize treatment goals and choices.
A mutation is a change in a DNA sequence that can be caused by errors during DNA replication, exposure to mutagens like radiation or chemicals, or infection by viruses. Mutations can be passed on to offspring or occur somatically in body cells. Some mutations can cause genetic disorders like sickle cell anemia, Down syndrome, or Edwards syndrome, while others may have no effect or even provide an advantage to survival. Mutants arise from mutations in existing genomes due to errors in DNA replication or repair.
Les principales techniques sont les réactions de précipitation, les réactions d'agglutination et les réactions de neutralisation.
La plupart de ces techniques utilisent les propriétés des anticorps monoclonaux.
Leur affinité et leur spécificité de liaison à leur cible fait d'eux des outils incontournables de détection.
Ils permettent de déterminer la présence d'un épitope particulier dans un échantillon, permettant ainsi dans les techniques comme le western blot ou l'ELISA de détecter des protéines, ou des modifications particulières de protéine (phosphorylation, acétylation, etc.).
Biotechnology is the use of living organisms to develop useful products. Modern biotechnology techniques include isolating DNA, inserting genes into vectors, and transforming host cells. Applications include producing Bt crops for pest resistance, producing vaccines and diagnosing diseases. New advances include artificial lymph nodes, non-invasive cancer detection from saliva, smart contact lenses to monitor eye pressure, and machines that can scan the liver non-invasively. Biotechnology continues to progress rapidly with applications in agriculture, medicine, and other fields.
This document provides an overview of protein therapeutics. It discusses how mutations or abnormalities in any of the estimated 25,000-40,000 human genes can result in disease. Protein therapeutics aim to alleviate such diseases. The timeline shows key developments in protein therapeutics from 1953 to present. Therapeutic proteins are classified and the challenges of delivering them are discussed. A case study examines efforts to achieve a cure for HIV infection through complete virus suppression while minimizing toxicity. Further work is needed to optimize treatment goals and choices.
Recombinant DNA is created using molecular cloning techniques to combine DNA from multiple sources into new sequences. There are three main methods: transformation, phage introduction, and non-bacterial transformation. Transformation involves inserting DNA into bacterial host cells like E. coli, while non-bacterial transformation uses direct microinjection or biolistics in non-bacterial cells. Phage introduction uses bacteriophages to introduce DNA. Recombinant DNA technology has important applications in agriculture, medicine, and other fields.
Monoclonal and polyclonal antibodies can be produced through different methods. Monoclonal antibodies are produced using hybridoma technology, which involves fusing myeloma cells with antibody-producing B cells to create immortal hybridoma cell lines. Kohler and Milstein developed this technique in 1975. Polyclonal antibodies involve immunizing an animal to produce a mixture of antibodies against various epitopes of an antigen. Monoclonal antibodies are highly specific to a single epitope, while polyclonal antibodies detect multiple epitopes but with less specificity. Monoclonal antibodies provide an unlimited supply of consistent, specific antibodies and are widely used in research and therapeutic applications.
De l'antigène à l'anticorps - Présentation de la 2e édition du Cours international « Atelier Paludisme » - AHMED Haoudhoit - MINISTERE de la SANTE de l'UNION des COMORES - Chargée du laboratoire au CSK de Mvouni - haoumed@hotmail.com
This document discusses microbial biotransformation of steroids. It begins with an introduction and definitions of biotransformation. It then covers the history of microbial steroid transformations, advantages of biotransformation, and the phases and requirements of the process. Methods used like oxidation and halogenation are described. Examples of microbial hydroxylation and epoxidation reactions are given. The procedure for carrying out biotransformations is outlined, including using nutritionally rich media, solvent extraction of products, and analytical techniques for structure elucidation. Microbial biotransformations are shown to be useful for producing industrial compounds like steroids and antibiotics.
The document discusses recombinant DNA technology. It begins by defining recombinant DNA as DNA molecules formed by joining DNA from two different species. It then discusses the key steps in recombinant DNA technology, including isolating DNA, cutting DNA with restriction enzymes, joining DNA together with DNA ligase, and amplifying the recombinant DNA by inserting it into a host cell. The document also covers applications of recombinant DNA technology such as producing insulin, vaccines, and monoclonal antibodies.
RESTRICTION ENDONUCLEASES & DNA LIGASES SMGsajigeorge64
Restriction endonucleases are enzymes found in bacteria that recognize specific nucleotide sequences in DNA and cut the DNA at those sites. This acts as a defense mechanism for bacteria by destroying foreign DNA, such as that from viruses. There are several types of restriction endonucleases, but type II are most useful for genetic engineering as they cut DNA at predictable, site-specific locations. The resulting DNA fragments can be joined back together via DNA ligases. Restriction endonucleases have four- to six-letter recognition sequences that are palindromic, and they produce sticky or blunt ends depending on whether cuts are offset or at the same position.
Pharmaceutical biotechnology ..in that different blotting techniques such as ELISA , western blotting and southern blotting.There applications and their advantage and disadvantage with their diagrams
It discuss about early life, CAREER, BIOTECHNOLOGY AND HIM, THE STORY, THE EVOLUTION OF BIOTECHNOLOGY, HE CLASSIFIED Biotechnology IN…CONTRIBUTIONS & conclusion
Immunoblotting assays such as Western blotting allow detection of specific proteins in complex mixtures by separating proteins by gel electrophoresis, transferring them to a membrane, and using antibodies to identify target proteins on the membrane. The presentation provides details on the key steps of tissue preparation, gel electrophoresis, protein transfer, blocking, detection using labeled antibodies, analysis, and applications of immunoblotting assays like Western blotting.
Immunodiffusion techniques such as radial immunodiffusion, Ouchterlony double diffusion, and immunoelectrophoresis can be used to detect and quantify antigens and antibodies through the formation of precipitin lines. These techniques utilize the diffusion of antigens and antibodies through a semi-solid medium like agar to form visible precipitin lines where the antigens and antibodies combine. They can be used to diagnose diseases, detect immunodeficiencies, and assess the purity and concentration of antigens and antibodies.
This document describes the double immunodiffusion technique, which involves allowing antigens and antibodies to diffuse toward each other in a gel to form visible precipitate lines. It details the historical background, principle, methodology, interpretation of results, applications including pregnancy tests and fungal antigen identification, and recent research using modifications of the technique.
Precipitation reactions occur when an antibody and soluble antigen interact in solution, forming a visible precipitate. A precipitin curve can be created by plotting the amount of precipitate formed against increasing concentrations of antigen. Immunoelectrophoresis techniques separate antigens by charge and detect antigen-antibody reactions using precipitation lines formed in an agar gel containing antibodies. Crossed immunoelectrophoresis further separates proteins through two perpendicular rounds of electrophoresis and antibody detection.
Immunoprecipitation: Procedure, Analysis and Applicationsajithnandanam
Immunoprecipitation is a precipitaion technique which allows the isolation of protein or protein complex from biological samples.
Incubate sample with antibody against protein of interest.
Separate antibody-protein complex from remaining sample
Analysis
O documento descreve diferentes métodos para quantificação de proteínas, incluindo absorvância a 280 ou 205 nm, BCA, biureto, Bradford e Lowry. Cada método possui limitações como interferência de outros compostos e variação na ligação ao corante entre diferentes proteínas. O método de Coomassie Dry possui o tempo total de ensaio mais curto, enquanto o Micro BCA requer o maior tempo.
Recombinant DNA is created using molecular cloning techniques to combine DNA from multiple sources into new sequences. There are three main methods: transformation, phage introduction, and non-bacterial transformation. Transformation involves inserting DNA into bacterial host cells like E. coli, while non-bacterial transformation uses direct microinjection or biolistics in non-bacterial cells. Phage introduction uses bacteriophages to introduce DNA. Recombinant DNA technology has important applications in agriculture, medicine, and other fields.
Monoclonal and polyclonal antibodies can be produced through different methods. Monoclonal antibodies are produced using hybridoma technology, which involves fusing myeloma cells with antibody-producing B cells to create immortal hybridoma cell lines. Kohler and Milstein developed this technique in 1975. Polyclonal antibodies involve immunizing an animal to produce a mixture of antibodies against various epitopes of an antigen. Monoclonal antibodies are highly specific to a single epitope, while polyclonal antibodies detect multiple epitopes but with less specificity. Monoclonal antibodies provide an unlimited supply of consistent, specific antibodies and are widely used in research and therapeutic applications.
De l'antigène à l'anticorps - Présentation de la 2e édition du Cours international « Atelier Paludisme » - AHMED Haoudhoit - MINISTERE de la SANTE de l'UNION des COMORES - Chargée du laboratoire au CSK de Mvouni - haoumed@hotmail.com
This document discusses microbial biotransformation of steroids. It begins with an introduction and definitions of biotransformation. It then covers the history of microbial steroid transformations, advantages of biotransformation, and the phases and requirements of the process. Methods used like oxidation and halogenation are described. Examples of microbial hydroxylation and epoxidation reactions are given. The procedure for carrying out biotransformations is outlined, including using nutritionally rich media, solvent extraction of products, and analytical techniques for structure elucidation. Microbial biotransformations are shown to be useful for producing industrial compounds like steroids and antibiotics.
The document discusses recombinant DNA technology. It begins by defining recombinant DNA as DNA molecules formed by joining DNA from two different species. It then discusses the key steps in recombinant DNA technology, including isolating DNA, cutting DNA with restriction enzymes, joining DNA together with DNA ligase, and amplifying the recombinant DNA by inserting it into a host cell. The document also covers applications of recombinant DNA technology such as producing insulin, vaccines, and monoclonal antibodies.
RESTRICTION ENDONUCLEASES & DNA LIGASES SMGsajigeorge64
Restriction endonucleases are enzymes found in bacteria that recognize specific nucleotide sequences in DNA and cut the DNA at those sites. This acts as a defense mechanism for bacteria by destroying foreign DNA, such as that from viruses. There are several types of restriction endonucleases, but type II are most useful for genetic engineering as they cut DNA at predictable, site-specific locations. The resulting DNA fragments can be joined back together via DNA ligases. Restriction endonucleases have four- to six-letter recognition sequences that are palindromic, and they produce sticky or blunt ends depending on whether cuts are offset or at the same position.
Pharmaceutical biotechnology ..in that different blotting techniques such as ELISA , western blotting and southern blotting.There applications and their advantage and disadvantage with their diagrams
It discuss about early life, CAREER, BIOTECHNOLOGY AND HIM, THE STORY, THE EVOLUTION OF BIOTECHNOLOGY, HE CLASSIFIED Biotechnology IN…CONTRIBUTIONS & conclusion
Immunoblotting assays such as Western blotting allow detection of specific proteins in complex mixtures by separating proteins by gel electrophoresis, transferring them to a membrane, and using antibodies to identify target proteins on the membrane. The presentation provides details on the key steps of tissue preparation, gel electrophoresis, protein transfer, blocking, detection using labeled antibodies, analysis, and applications of immunoblotting assays like Western blotting.
Immunodiffusion techniques such as radial immunodiffusion, Ouchterlony double diffusion, and immunoelectrophoresis can be used to detect and quantify antigens and antibodies through the formation of precipitin lines. These techniques utilize the diffusion of antigens and antibodies through a semi-solid medium like agar to form visible precipitin lines where the antigens and antibodies combine. They can be used to diagnose diseases, detect immunodeficiencies, and assess the purity and concentration of antigens and antibodies.
This document describes the double immunodiffusion technique, which involves allowing antigens and antibodies to diffuse toward each other in a gel to form visible precipitate lines. It details the historical background, principle, methodology, interpretation of results, applications including pregnancy tests and fungal antigen identification, and recent research using modifications of the technique.
Precipitation reactions occur when an antibody and soluble antigen interact in solution, forming a visible precipitate. A precipitin curve can be created by plotting the amount of precipitate formed against increasing concentrations of antigen. Immunoelectrophoresis techniques separate antigens by charge and detect antigen-antibody reactions using precipitation lines formed in an agar gel containing antibodies. Crossed immunoelectrophoresis further separates proteins through two perpendicular rounds of electrophoresis and antibody detection.
Immunoprecipitation: Procedure, Analysis and Applicationsajithnandanam
Immunoprecipitation is a precipitaion technique which allows the isolation of protein or protein complex from biological samples.
Incubate sample with antibody against protein of interest.
Separate antibody-protein complex from remaining sample
Analysis
O documento descreve diferentes métodos para quantificação de proteínas, incluindo absorvância a 280 ou 205 nm, BCA, biureto, Bradford e Lowry. Cada método possui limitações como interferência de outros compostos e variação na ligação ao corante entre diferentes proteínas. O método de Coomassie Dry possui o tempo total de ensaio mais curto, enquanto o Micro BCA requer o maior tempo.
The document discusses immunodiffusion techniques for detecting antigens and antibodies, specifically the Ouchterlony double immunodiffusion assay. It provides background on immunodiffusion basics, including antigen-antibody reactions, precipitation, and single and double immunodiffusion. It also defines key terms like antigen, antibody, monoclonal and polyclonal antibodies, and discusses their characteristics and functions.
1. The document reports on serological tests conducted to detect Brucella abortus and Salmonella in samples X, Y, and Z.
2. The Brucella test found samples X and Y tested positive for B. abortus antibodies while sample Z tested negative.
3. The Salmonella test found sample X tested positive for Salmonella antigens but sample Y tested negative.
Antigen and antibody interaction is the basis of serological testing. There are several types of serological tests that detect this interaction, including precipitation, agglutination, hemagglutination, enzyme-linked immunosorbent assay (ELISA), Western blot, hemagglutination inhibition, and immunofluorescence. These tests exploit the formation of antigen-antibody complexes to diagnose diseases, identify pathogens, and detect proteins.
This document discusses various immuno-diagnostic techniques used to detect molecules like antigens, antibodies, hormones, and DNA. It describes techniques like ELISA, RIA, western blotting, and PCR that use specific molecular interactions like antigen-antibody binding, enzyme-substrate reactions, and DNA complementarity. Examples are given of using these techniques to detect infections like HIV, hepatitis B, toxoplasmosis, and for hormone analysis. The principles of techniques like direct and sandwich ELISA, immunodiffusion, agglutination tests and their applications in immunodiagnosis are explained.
Western Blotting - Technical Tips and Troubleshooting Proteintech Group
This document provides guidance on performing and troubleshooting Western blot experiments. It discusses key steps such as sample preparation, gel electrophoresis, transfer to a membrane, blocking, antibody detection and analysis. Tips are provided for optimizing detection of low molecular weight proteins, choosing an appropriate membrane, using proper controls, and troubleshooting issues like nonspecific binding, weak signals and high backgrounds. Contact information is included for technical support.
Immunoprecipitation (IP) is a technique used to purify and enrich proteins of interest from a protein mixture using antibodies. The general IP protocol involves incubating a cell lysate sample containing the target protein with antibody-bound beads, washing away non-specifically bound proteins, and then eluting the immunoprecipitated protein off the beads. Key factors that influence IP include the composition of wash and elution buffers, the type of solid support used, antibody specificity and amount, and pre-clearing the lysate sample. Controls like isotype controls and negative controls without antibody help assess the specificity of the IP results.
Lab report that discusses the antigen-antibody precipitation reaction using the Ouchterlony Double Diffusion Technique.
Created by: Annisa Hayatunnufus
Bachelor of Pharmacy
Management & Science University
Immunoprecipitation is a technique to isolate a specific protein from a mixture using an antibody that binds to that protein. There are two main methods: traditional IP and crosslink IP. Traditional IP recovers both the antibody and antigen, which can make identifying the antigen difficult if they have similar sizes. Crosslink IP covalently attaches the antibody to beads, allowing isolation of just the antigen without antibody contamination to easily identify and analyze the target protein. However, in some rare cases the traditional method may work better, such as if the antibody is unstable or the antibody-antigen binding is too strong for elution.
ELISA (enzyme-linked immunosorbent assay) is a biochemical technique used to detect the presence of antibodies and antigens in a liquid sample. It relies on an enzyme-linked antibody or antigen to detect the target protein. There are different types of ELISA including direct, indirect, sandwich, and competitive. The ELISA process involves coating a plate with an antigen or antibody, adding a sample and enzyme-linked antibody, washing unbound material, and detecting the enzyme's product to quantify the target. ELISAs are widely used in medical testing, food safety, and disease detection.
The ELISA (enzyme-linked immunosorbent assay) is a popular biochemistry assay that uses antibodies and color change to identify a substance. It involves using an enzyme-linked antibody to detect antigen-antibody binding, where the enzyme converts a colorless substrate into a colored product. There are several types of ELISA including indirect, direct, sandwich, and competitive ELISA. ELISA has various applications such as screening blood donations, measuring hormone levels, and detecting infections and allergens.
Impact des Critères Environnementaux, Sociaux et de Gouvernance (ESG) sur les...mrelmejri
J'ai réalisé ce projet pour obtenir mon diplôme en licence en sciences de gestion, spécialité management, à l'ISCAE Manouba. Au cours de mon stage chez Attijari Bank, j'ai été particulièrement intéressé par l'impact des critères Environnementaux, Sociaux et de Gouvernance (ESG) sur les décisions d'investissement dans le secteur bancaire. Cette étude explore comment ces critères influencent les stratégies et les choix d'investissement des banques.
Conseils pour Les Jeunes | Conseils de La Vie| Conseil de La JeunesseOscar Smith
Besoin des conseils pour les Jeunes ? Le document suivant est plein des conseils de la Vie ! C’est vraiment un document conseil de la jeunesse que tout jeune devrait consulter.
Voir version video:
➡https://youtu.be/7ED4uTW0x1I
Sur la chaine:👇
👉https://youtube.com/@kbgestiondeprojets
Aimeriez-vous donc…
-réussir quand on est jeune ?
-avoir de meilleurs conseils pour réussir jeune ?
- qu’on vous offre des conseils de la vie ?
Ce document est une ressource qui met en évidence deux obstacles qui empêchent les jeunes de mener une vie épanouie : l'inaction et le pessimisme.
1) Découvrez comment l'inaction, c'est-à-dire le fait de ne pas agir ou d'agir alors qu'on le devrait ou qu'on est censé le faire, est un obstacle à une vie épanouie ;
> Comment l'inaction affecte-t-elle l'avenir du jeune ? Que devraient plutôt faire les jeunes pour se racheter et récupérer ce qui leur appartient ? A découvrir dans le document ;
2) Le pessimisme, c'est douter de tout ! Les jeunes doutent que la génération plus âgée ne soit jamais orientée vers la bonne volonté. Les jeunes se sentent toujours mal à l'aise face à la ruse et la volonté politique de la génération plus âgée ! Cet état de doute extrême empêche les jeunes de découvrir les opportunités offertes par les politiques et les dispositifs en faveur de la jeunesse. Voulez-vous en savoir plus sur ces opportunités que la plupart des jeunes ne découvrent pas à cause de leur pessimisme ? Consultez cette ressource gratuite et profitez-en !
En rapport avec les " conseils pour les jeunes, " cette ressource peut aussi aider les internautes cherchant :
➡les conseils pratiques pour les jeunes
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➡Quels sont les bienfaits de la jeunesse ?
➡Quels sont les 3 qualités de la jeunesse ?
➡Comment gérer les problèmes des adolescents ?
➡les conseils de jeunes
➡guide de conseils de jeunes
Cycle de Formation Théâtrale 2024 / 2025Billy DEYLORD
Pour la Saison 2024 / 2025, l'association « Le Bateau Ivre » propose un Cycle de formation théâtrale pour particuliers amateurs et professionnels des arts de la scène enfants, adolescents et adultes à l'Espace Saint-Jean de Melun (77). 108 heures de formation, d’octobre 2024 à juin 2025, à travers trois cours hebdomadaires (« Pierrot ou la science de la Scène », « Montage de spectacles », « Le Mime et son Répertoire ») et un stage annuel « Tournez dans un film de cinéma muet ».
Formation M2i - Onboarding réussi - les clés pour intégrer efficacement vos n...M2i Formation
Améliorez l'intégration de vos nouveaux collaborateurs grâce à notre formation flash sur l'onboarding. Découvrez des stratégies éprouvées et des outils pratiques pour transformer l'intégration en une expérience fluide et efficace, et faire de chaque nouvelle recrue un atout pour vos équipes.
Les points abordés lors de la formation :
- Les fondamentaux d'un onboarding réussi
- Les outils et stratégies pour un onboarding efficace
- L'engagement et la culture d'entreprise
- L'onboarding continu et l'amélioration continue
Formation offerte animée à distance avec notre expert Eric Collin
Newsletter SPW Agriculture en province du Luxembourg du 12-06-24BenotGeorges3
Les informations et évènements agricoles en province du Luxembourg et en Wallonie susceptibles de vous intéresser et diffusés par le SPW Agriculture, Direction de la Recherche et du Développement, Service extérieur de Libramont.
Le fichier :
Les newsletters : https://agriculture.wallonie.be/home/recherche-developpement/acteurs-du-developpement-et-de-la-vulgarisation/les-services-exterieurs-de-la-direction-de-la-recherche-et-du-developpement/newsletters-des-services-exterieurs-de-la-vulgarisation/newsletters-du-se-de-libramont.html
Bonne lecture et bienvenue aux activités proposées.
#Agriculture #Wallonie #Newsletter #Recherche #Développement #Vulgarisation #Evènement #Information #Formation #Innovation #Législation #PAC #SPW #ServicepublicdeWallonie
Tp17 Test d'immunodiffusion sur gel ; test d'ouchterlony
1. LE TEST D’IMMUNODIFFUSION OU TEST D’OUCHTERLONY : RECHERCHE
D’UN ANTIGÈNE
A des fins expérimentales, des lapins reçoivent par injections un antigène. Ils
produisent alors des anticorps spécifiques contenus dans leur sérum ; ceux-ci peuvent
être mis en évidence par la méthode d’Ouchterlony.
On cherche à identifier l’antigène injecté à un lapin.
Matériel :
- deux petites boîtes de Pétri contenant du gel d'agar; une pipette 10mL et pipeteur,
un tube emporte-pièce (en l’occurrence une paille !) ;
- un marqueur (pour marquer la boîte de Pétri) ;
- sérum du lapin (= S) ; il contient des anticorps dirigés contre l’antigène inconnu
injecté ;
- eau distillée (= E), 4 solutions d’antigènes protéiques : pancréatine = P ; caséine = C ;
hémoglobine = H ; albumine de sérum de bœuf (BSA) = B ;
– un compte-goutte pour chaque produit ; une lampe de bureau et une petite feuille
de papier noir.
Activités et conditions des activités
1. Après lecture du protocole de la fiche technique (partie I et II ), choisir la
disposition des produits dans la boîte de Pétri et l’indiquer sur le schéma de la fiche
réponse . Justifier ce choix.
Appeler l’examinateur pour vérifier et obtenir éventuellement un document de
secours
2. Réaliser les parties I et II du protocole de la fiche technique
Appeler l’examinateur pour obtenir les résultats.
3. Représenter sur la fiche réponse le résultat fourni. Réaliser deux schémas qui
représentent au niveau moléculaire :
- la formation de l’arc de précipitation,
- l’absence d’arc.
Pour la représentation des anticorps, utiliser le modèle de la fiche réponse.
4. A partir des résultats fournis, déterminer quel est l’antigène injecté au lapin.
Justifier votre réponse.
2. Fiche technique
Principe de la méthode d’Ouchterlony
C’est l’immunodiffusion sur gel : les solutions déposées dans les puits creusés dans le
gel diffusent de façon homogène dans toutes les directions autour du puits. Deux
auréoles de diffusion peuvent donc entrer en contact lorsqu’elles ont suffisamment
progressé. Cette zone de contact reste invisible s’il n’y a pas de réaction entre les
deux solutions. Quand il y a réaction entre les solutions, il se forme un arc de
précipitation visible à l’œil nu. Celui-ci est dû à l’interaction entre de nombreux
anticorps et les antigènes spécifiques, entraînant la formation d’un complexe immun.
NB : le temps de réaction avec les produits véritables est de l’ordre de 24h ; vous
manipulez ici sur des produits de substitution mimant les réactions réelles mais
permettant une lecture des résultats au bout de 40 min. Cependant, après avoir
réalisé le protocole, vous disposerez, pour lire les résultats, d’une boîte préparée à
l’avance.
PROTOCOLE
I- Préparation du test
1. Creuser les puits nécessaires dans le gel d’Agar d’une boîte de Pétri.
2. Utiliser le modèle schématisé ci-contre pour répartir les
puits nécessaires.
S’exercer avec la deuxième boîte pour creuser les puits
avec l’emporte-pièce.
II- Réalisation du test
1. Marquer sur la boîte de Pétri la disposition des produits à déposer dans les puits
permettant de révéler la réaction de l’anticorps étudié avec les différents antigènes
proposés.
2. Remplir les puits : le produit, prélevé dans un tube avec un compte goutte propre,
doit être déposé dans le puits approprié sans débordement ni bulles et sans
endommager le gel d’agar.
3. Observer les résultats fournis sur fond noir et en éclairage rasant.
3. Fiche réponse. NOM – Prénom :
Schéma à compléter
Modèle de l'anticorps pour la schématisation :
Schémas