OVA (257-264), FAM labeled

Product Name: OVA (257-264), FAM labeled

Sequence One Letter Code: 5-FAM-SIINFEKL-NH2

Sequence Three Letter Code: 5-FAM-Ser-Ile-Ile-Asn-Phe-Glu-Lys-Leu-NH2

Chemical Formula:C66H85N11O18

Molecular Weight: 1320.5

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C Protected from light

Research Area: Inflammation and Immunology Research

Source / Species: chicken

Conjugation: Conjugated

Conjugation Type: Fluorescent dyes

Code Nacres: NA.26

Application: This FAM-labeled ovalbumin peptide corresponds to residues 257–264, a well-characterized class I epitope restricted by murine MHC class I molecule H-2Kᵇ. The sequence is commonly used in mouse immunology models to study antigen presentation and CD8⁺ cytotoxic T lymphocyte responses. Conjugation with the fluorescein (FAM) fluorophore enables sensitive detection with excitation and emission maxima near 494 and 521 nm. The fluorescent tag allows tracking of peptide uptake, MHC loading, and antigen presentation in living cells. This peptide is suitable for fluorescence microscopy, flow cytometry, and functional immune assays. It supports studies of antigen processing pathways, T-cell activation, and immune monitoring in experimental immunology and vaccine development research.

Current Research: Understanding how the immune system recognizes and responds to antigens is central to modern immunology. Experimental peptide epitopes derived from well-characterized proteins are widely used to investigate antigen processing, MHC presentation, and T-cell activation. One of the most extensively studied model antigens is ovalbumin (OVA), a protein commonly used in mouse immunology research. The OVA (257–264) peptide, also known as the SIINFEKL epitope, represents a classical MHC class I–restricted antigen recognized by CD8⁺ cytotoxic T lymphocytes. When labeled with a fluorescent probe such as fluorescein (FAM), this peptide becomes a powerful tool for tracking antigen presentation and immune activation in real time. The OVA (257–264) Epitope in Immunology Research The peptide corresponding to ovalbumin residues 257–264 is one of the best-characterized antigenic epitopes in experimental immunology. It is specifically presented by the murine MHC class I molecule H-2Kᵇ, making it a standard reagent for studying antigen-specific CD8⁺ T-cell responses in mouse models. Once presented on the cell surface by MHC class I molecules, the OVA (257–264) epitope can be recognized by cytotoxic T lymphocytes (CTLs). These T cells play a crucial role in immune defense by identifying and eliminating infected or abnormal cells. Because of its reproducible and well-defined immune recognition, the SIINFEKL epitope has become a widely used model antigen for investigating: Antigen processing pathways MHC class I peptide loading CD8⁺ T-cell activation and cytotoxic responses Immune monitoring in vaccine and immunotherapy studies This peptide has also been used extensively in transgenic mouse models such as OT-I mice, whose CD8⁺ T cells specifically recognize the OVA (257–264) epitope. Fluorescent Labeling with FAM To expand its experimental applications, the OVA (257–264) peptide can be conjugated with fluorescein (FAM), a widely used fluorescent dye. FAM exhibits strong fluorescence with excitation and emission maxima around 494 nm and 521 nm, making it compatible with many standard fluorescence detection systems. The fluorescent labeling allows researchers to directly visualize and quantify peptide behavior in biological systems. Because the FAM tag emits a bright signal under appropriate excitation conditions, the labeled peptide can be detected with high sensitivity using common imaging and analytical techniques. This fluorescence capability transforms the peptide from a simple antigenic epitope into a multifunctional probe for studying immune processes at the cellular level. Monitoring Antigen Processing and Presentation One of the most important uses of the FAM-labeled OVA (257–264) peptide is the study of antigen uptake and presentation pathways. Antigen-presenting cells (APCs), such as dendritic cells and macrophages, process peptides and load them onto MHC molecules for display on the cell surface. The fluorescent label enables researchers to track several steps in this process, including: Cellular uptake of antigenic peptides Intracellular trafficking and processing Loading of peptides onto MHC class I molecules Surface presentation to CD8⁺ T cells By monitoring fluorescence signals, scientists can determine how efficiently peptides are internalized, processed, and presented by immune cells. Applications in Imaging and Immune Assays Because of its fluorescent properties, the FAM-labeled OVA (257–264) peptide is compatible with multiple experimental techniques used in immunology laboratories. Common applications include: Fluorescence microscopy Researchers can visualize peptide uptake and intracellular localization in living or fixed cells, helping to clarify antigen trafficking pathways. Flow cytometry Fluorescent detection allows quantitative analysis of peptide binding or presentation in large populations of immune cells. Functional T-cell assays The peptide can be used to stimulate antigen-specific CD8⁺ T cells while simultaneously enabling fluorescent monitoring of peptide interactions. These approaches allow investigators to connect antigen presentation dynamics with functional immune responses. Relevance to Vaccine Development and Immunotherapy The OVA (257–264) epitope is frequently used as a model system in studies focused on vaccine development and immune monitoring. Researchers can use fluorescently labeled peptides to evaluate how efficiently candidate vaccines promote antigen uptake, presentation, and T-cell activation. Because CD8⁺ cytotoxic T cells are critical for eliminating virus-infected or cancerous cells, understanding the mechanisms that enhance antigen presentation is essential for designing effective immunotherapies. The FAM-labeled OVA peptide therefore serves as a convenient experimental platform for exploring strategies that improve immune activation. A Versatile Probe for Experimental Immunology The FAM-labeled OVA (257–264) peptide combines a well-characterized MHC class I epitope with the detection advantages of fluorescent labeling. This combination allows researchers to simultaneously study antigen presentation, visualize peptide behavior in cells, and evaluate T-cell responses. Through its compatibility with fluorescence microscopy, flow cytometry, and immune assays, the peptide has become a versatile tool for investigating antigen processing pathways, CD8⁺ T-cell activation, and immune system dynamics. As immunology research continues to advance, fluorescent antigenic peptides such as this one remain essential for uncovering the cellular mechanisms that shape adaptive immune responses.