ANTISERA Flashcards
Who laid laid the foundation for immunology?
Emil van Behring had
shown that immunization
created a blood-born
factor that could be
transferred to protect
against diphtheria. by demonstrating that immunization could produce a blood-borne factor, later identified as antibodies, which could be transferred to provide protection against diphtheria.
what is immunization
Immunization is the process by which an individual’s immune system becomes fortified against an agent (known as the immunogen). When the immune system is exposed to molecules that are foreign to the body, called antigens, it triggers an immune response. The process of immunization can occur naturally or artificially
What is an Immunoassay?
An immunoassay is a biochemical test that measures the presence or concentration of a substance, often an antigen, in a solution through the use of an antibody or antibodies. Immunoassays for SARS-CoV-2 antigens are designed to detect specific proteins from the virus, typically the nucleocapsid or spike proteins, in samples such as nasal or throat swabs.
Lateral Flow Assays (LFAs)
Also known as rapid antigen tests, these are quick and easy-to-use tests that can be performed at the point of care. They typically provide results within 15-30 minutes.
The test strip contains antibodies that bind to the SARS-CoV-2 antigens if they are present in the sample. A visible line appears on the strip to indicate a positive result.
Enzyme-Linked Immunosorbent Assays (ELISAs)
These assays are more sensitive and are usually performed in a laboratory setting. They involve multiple steps where the antigen binds to an antibody attached to a solid surface, and then a secondary antibody linked to an enzyme reacts to produce a detectable signal.
ELISAs can quantify the amount of viral antigen present, providing more detailed information compared to rapid tests
What is a GMO Immunoassay?
An immunoassay for GMO detection is a biochemical test that uses antibodies to identify and measure specific proteins that are unique to genetically modified organisms. These proteins are typically those expressed by the inserted genetic material in the GMO.
immunoassay test for the CP4 protein that makes crops tolerant to Roundup® herbicides.
What are Food Allergen Tests?
Food allergen tests are designed to detect specific proteins in food that can cause allergic reactions in sensitive individuals. These tests use antibodies that bind to these allergenic proteins, allowing for their identification and quantification.
Types of Antibody-Based Food Allergen Tests
Enzyme-Linked Immunosorbent Assays (ELISAs):
ELISAs are widely used for detecting food allergens. They involve binding allergen-specific antibodies to a solid surface, applying the food sample, and then adding a secondary antibody that produces a measurable signal, typically a color change.
ELISAs can be both qualitative (indicating the presence or absence of an allergen) and quantitative (measuring the amount of allergen).
Lateral Flow Devices (LFDs):
Also known as rapid tests or strip tests, these are user-friendly and provide quick results. A sample is applied to a test strip, and if the allergen is present, it binds to antibodies on the strip and produces a visible line.
LFDs are typically used for on-site testing and are qualitative or semi-quantitative.
Western Blotting:
This technique involves separating proteins by gel electrophoresis, transferring them to a membrane, and detecting specific allergens using antibodies.
Western blotting is highly specific and is used for confirming the presence of allergens detected by other methods.
BioKits
BioKits are a series of antibody-based test kits specifically designed for detecting various food allergens and genetically modified organisms (GMOs) in food products. These kits leverage immunoassay technology to provide reliable, rapid, and user-friendly testing solutions for the food industry.
The kits are designed to detect specific proteins (allergens) or genetic modifications (GMOs) in food samples, ensuring compliance with labeling regulations and safeguarding consumer health.
Antibody-Based Applications for Raw Meat Analysis
Enzyme-Linked Immunosorbent Assays (ELISAs): ELISAs can detect pathogens like Salmonella, Escherichia coli (E. coli), Listeria monocytogenes, and Campylobacter.
Where are antibodies used in everyday life?
conventional pregnancy tests
* rapid tests in the doctor’s office
* at home
what are some Antibody-based applications?
-In vivo therapy
-In vivo diagnostic
-Vaccination
-Chromatography
(t.ex. affinity chromatography)
-Biosensors
(e.g. continous-flow measuremets in biosensors)
-Immunoblotting techniques
-Immunoprecipitation
(e.g. studies of protein-protein interactions)
-Immunofluorescence/histology
-Protein-DNA interactions
-Microarray techniques
(focussed assay to proteome-scale
analysis)
-Flow cytometry
-Qualitative analysis
(pregnancy test, drug test, HIV test,
bacterial infections)
-Quantitative analysis
(precipitation/nefelometri, competitive
analysis, non-competitive analysis)
what is In vivo therapy
In vivo therapy refers to medical treatments and interventions performed directly within a living organism. This term encompasses various therapeutic approaches where the treatment is administered in the body, as opposed to in vitro therapies, which are conducted outside the body in a controlled laboratory environment. In vivo therapies can target diseases at the molecular, cellular, or systemic level and include a broad range of techniques and applications.
In vivo diagnostic
In vivo diagnostics refer to medical diagnostic techniques and procedures performed directly within a living organism to detect and monitor diseases or medical conditions. These methods enable real-time assessment of biological processes in their natural context, providing valuable information for accurate diagnosis, disease progression monitoring, and treatment efficacy evaluation.
Vaccination
Vaccination works by introducing antigens (substances that the immune system recognizes as foreign) into the body. These antigens are typically derived from the pathogen itself, either in a weakened or inactivated form, or as parts of the pathogen such as proteins or sugars. The immune system responds to these antigens by producing antibodies and memory cells. If the vaccinated individual is later exposed to the actual pathogen, their immune system can quickly recognize and attack it, preventing illness.
Chromatography
(t.ex. affinity chromatography)
It involves the separation of components in a mixture based on their differential distribution between two phases: a stationary phase and a mobile phase. One particularly useful type of chromatography is affinity chromatography, which selectively purifies target molecules based on their specific interactions with immobilized ligands on the stationary phase.
Antibody Purification: Antibodies can be purified from serum or cell culture supernatants using affinity chromatography columns containing immobilized protein A or protein G
Biosensors
(e.g. continous-flow measuremets in biosensors)
Antibody-based biosensors are analytical devices that utilize antibodies as recognition elements to detect specific target molecules, such as proteins, pathogens, or environmental contaminants. These biosensors convert the binding events between antibodies and target molecules into measurable signals, providing rapid and sensitive detection capabilities. Continuous-flow measurements in biosensors are a common approach to enable real-time monitoring of target analytes.
Immunoblotting techniques
also known as Western blotting, is a widely used laboratory technique for detecting specific proteins in a complex mixture of proteins extracted from cells or tissues. This technique combines gel electrophoresis for protein separation with antibody-based detection for protein identification.
Immunoprecipitation
(e.g. studies of protein-protein interactions)
isolation and purification of specific proteins or protein complexes from complex biological samples, such as cell lysates or tissue homogenates, based on their interactions with specific antibodies.
Immunofluorescence/histology
Immunofluorescence (IF)
Principle: Immunofluorescence utilizes the selective binding of fluorescently labeled antibodies to specific target molecules (e.g., proteins) within cells or tissues.
Procedure:
Sample Preparation: Cells or tissue sections are fixed, permeabilized (if necessary), and blocked to preserve cellular structures and reduce nonspecific binding.
Primary Antibody Incubation: Samples are incubated with primary antibodies specific to the target molecule(s) of interest.
Secondary Antibody Incubation: Fluorescently labeled secondary antibodies, which recognize the primary antibodies, are applied to the samples.
Washing: Unbound antibodies are removed by washing steps to reduce background fluorescence.
Mounting: Samples are mounted with a mounting medium containing fluorescent dyes (e.g., DAPI for nuclear staining) to visualize cell structures.
Microscopic Imaging: The samples are examined using a fluorescence microscope to visualize the fluorescently labeled target molecules within cells or tissues.
Applications:
Visualization and localization of proteins, nucleic acids, and other molecules within cells and tissues.
Studies of cellular morphology, subcellular structures, and protein-protein interactions.
Diagnostic applications in pathology, immunology, and microbiology.
Histology
Principle: Histology involves the preparation of tissue samples for microscopic examination to study the structure, composition, and organization of tissues and organs.
Procedure:
Tissue Fixation: Tissues are fixed using chemical fixatives (e.g., formaldehyde) to preserve cellular structures and prevent decay.
Tissue Processing: Fixed tissues are dehydrated, embedded in a solid medium (e.g., paraffin wax or resin), and sectioned into thin slices (histological sections).
Staining: Sections are stained using various dyes or stains to highlight different tissue components, such as nuclei (hematoxylin), cytoplasm (eosin), connective tissue (Masson’s trichrome), and specific cell types (immunohistochemical staining).
Mounting: Stained sections are mounted onto glass slides and coverslipped for microscopic examination.
Microscopic Imaging: The prepared slides are examined using a light microscope to visualize tissue structures and patterns.
Applications:
Diagnosis of diseases and pathological conditions (histopathology).
Research studies of tissue development, morphology, and pathology.
Forensic analysis and comparative anatomy studies.
protein-DNA interactions
Techniques such as ChIP, EMSA, immunofluorescence, and immunohistochemistry provide insights into the dynamics, localization, and functional consequences of protein-DNA interactions
Microarray techniques
(focussed assay to proteome-scale
analysis)
Tissue Microarrays (TMAs):
Principle: Tissue microarrays are constructed by embedding multiple tissue samples into a single paraffin block. Thin sections are cut from the block, allowing simultaneous analysis of multiple tissue specimens on a single slide.
Procedure: Tissue sections are immunostained with specific antibodies, and protein expression patterns are analyzed by microscopy.
Applications: Studying protein expression in clinical samples, biomarker validation, cancer research.
Reverse Phase Protein Arrays (RPPAs):
Principle: RPPAs are used to analyze protein expression and post-translational modifications in large sample cohorts.
Procedure: Protein lysates from samples are printed onto a solid support as a microarray. The microarray is probed with specific antibodies, and protein levels are quantified using fluorescence or chemiluminescence.
Applications: Biomarker discovery, drug development, cancer research.
