Immunomagnetic beads (IMB) are a complex formed by binding molecules with immune activity, such as antibodies (or antigens), to the surface of magnetic particles through physical adsorption, chemical cross-linking, and other methods. It possesses both specificity of immune response and magnetic responsiveness. Magnetic particles, as carriers, are usually made of magnetic materials such as metals (such as iron, cobalt, nickel, etc.) or metal oxides (such as iron oxide), with particle sizes generally ranging from nanometers to micrometers.
The structure of immunomagnetic beads: Magnetic beads are composed of core metal particles (Fe2O3, Fe3O4), The core is composed of polymer materials wrapped around the outer layer (such as polystyrene, polyvinyl chloride) and functional ligands on the outermost layer (such as – NH2, – COOH, – OH, – CHO).
Working principle
Immune response binding stage: When immune magnetic beads are added to a sample containing a target antigen (or antibody), the antibody (or antigen) on the surface of the magnetic beads will specifically bind to the target antigen (or antibody). For example, when detecting cancer cells in the blood, antibodies conjugated to specific markers on the surface of cancer cells (such as epithelial cell adhesion molecules, EpCAM) on the surface of immunomagnetic beads will specifically bind to EpCAM on the surface of cancer cells, allowing the immunomagnetic beads to “capture” the cancer cells.
Magnetic separation stage: After completing the binding, an external magnetic field is applied, and due to the magnetic properties of the immunomagnetic beads themselves, they quickly separate the bound target molecules (or cells) from the sample solution. For example, placing a blood sample containing an immunomagnetic bead cancer cell complex in a magnetic field will attract the immunomagnetic bead cancer cells to one side of the magnetic field, while other components (such as blood cells, plasma proteins, etc.) remain in the solution, thus achieving the separation of cancer cells from other components.
Application areas of immunomagnetic beads
1. Biomedical research
(1) Cell sorting
Magnetic bead sorting, also known as immune magnetic bead cell sorting, mainly uses antibodies targeting specific cell surface antigens to label cells. The labeled cells crosslink with magnetic beads and are placed in a magnetic field to be adsorbed for selection or removal. Due to its speed and simplicity of operation, magnetic bead sorting is one of the most commonly used methods by researchers to separate specific cell subpopulations with high purity and activity.
There are many scenarios in which high-purity separated cells can be used for life science sorting experiments, such as disease modeling, cell therapy research, adoptive cell transplantation experiments in animal models, in vitro drug screening, and preparation of hybridomas.
Immunomagnetic bead cell sorting can separate highly pure cells from complex cell mixtures within a few minutes. When using nanoscale magnetic beads for cell sorting, the size and composition of the beads make them biodegradable and do not activate or affect the function and vitality of cells. The physiological functions of cells remain unchanged, so magnetic labeling of cells can be immediately used for analysis and subsequent experiments.
(2) Protein/antibody separation and purification
The immunomagnetic bead purification technology using antibody (protein) coating does not require complex chromatography equipment and has no limitation on sample clarity. It only requires a simple magnetic adsorption step to easily separate monoclonal antibodies from their expression products, effectively solving the shortcomings of traditional chromatography technology.
(3) Nucleic acid separation and purification
The binding of nucleic acids to magnetic beads mainly relies on electrostatic, hydrophobic, and hydrogen bonding interactions. Under the action of lysis buffer, DNA/RNA in cells or tissues is released. At this point, the surface modified superparamagnetic silica nano magnetic beads undergo “specific binding” with nucleic acid, forming a “nucleic acid magnetic bead complex”. Then, under the action of an external magnetic field, the complex is separated.
It can be widely applied in genome research, molecular evolution research, genetic disease research in medicine, mutation gene detection, tumor screening, HPV testing, HLA typing, transplant matching, forensic biology sample blood spot, semen spot, hair, cigarette butts and other on-site evidence testing, as well as forensic paternity testing, blood relationship identification, archaeology, biological experiments in primary, secondary and tertiary schools, and many other fields.
- Pathogen detection and enrichment: In microbiological research, immunomagnetic beads can be used to detect and enrich specific pathogens. For example, when detecting pathogenic E. coli in food, immune magnetic beads conjugated with anti E. coli antibodies are added to the food extract. After the magnetic beads bind to E. coli, the presence and quantity of E. coli are determined through magnetic separation and subsequent detection methods such as culture and PCR.
2. Clinical diagnosis and treatment
(1) Tumor diagnosis and monitoring: In early cancer diagnosis, immunomagnetic beads can be used to enrich circulating tumor cells (CTCs) in the blood, which can serve as biomarkers for early tumor diagnosis, treatment efficacy evaluation, and recurrence monitoring. For example, by detecting CTCs in the blood of lung cancer patients, doctors can understand the metastasis of the tumor and evaluate the effectiveness of treatment plans.
(2) Immunotherapy: In some immunotherapy methods, immunomagnetic beads can serve as carriers to deliver immune regulatory molecules. For example, coupling immunostimulatory factors onto immunomagnetic beads and delivering them to immune cells (such as T cells) through the specific binding of magnetic beads, enhances their immune activity, and is used to treat certain autoimmune diseases or tumors.
- Food safety testing
Can be used to detect harmful microorganisms (such as Salmonella, Listeria, etc.), toxins (such as aflatoxin), or genetically modified ingredients in food. For example, by adding immunomagnetic beads conjugated with anti Salmonella antibodies to the extract of food samples, magnetic separation and subsequent detection can quickly and sensitively detect the presence of Salmonella, ensuring food safety.
The advantages of immunomagnetic beads
- Strong specificity
Through the specific binding of antigens and antibodies, target molecules or cells can be accurately identified and captured, effectively reducing non-specific adsorption and background interference, and improving the accuracy of detection and separation.
- High separation efficiency
Under the action of an external magnetic field, immunomagnetic beads can quickly separate from the substrate liquid phase and enrich target molecules from complex biological samples, greatly reducing separation time and improving work efficiency.
- Easy to operate
It does not require complex instruments and equipment, and is suitable for fully automated workstations. It can achieve one click automated extraction, reducing the difficulty and error of manual operation.
- Good stability
It has good physical and chemical stability, and can maintain its performance under different experimental conditions, ensuring the reliability of experimental results.
- Diverse functions
It can be combined with various detection techniques and analysis methods, such as fluorescence labeling, chemiluminescence, etc., to achieve high-sensitivity detection and quantitative analysis of target molecules. It can also be used in multiple fields such as gene purification, protein purification, cell purification, microbial enrichment, etc.
Existing challenges of immunomagnetic beads
Non specific binding: Although the specificity is high, non-specific binding may still occur in some cases, leading to false positives in test results and affecting experimental accuracy.
Magnetic bead aggregation: Improper storage conditions or external factors may cause magnetic beads to aggregate, reducing specific surface area and activity, and affecting the binding efficiency with target molecules.
Expensive price: Especially for immune magnetic beads that have been specially modified or functionalized, the high cost limits their widespread application in large-scale experiments or clinical testing.
The impact on cellular function: During cell isolation and purification, it may interact with cell surface receptors or other molecules, interfere with normal physiological functions and biological behaviors of cells, and affect subsequent research and applications.
our solution
Faced with these challenges, SHBC is committed to providing you with higher quality immunomagnetic bead products!
In terms of preventing magnetic bead aggregation, we not only provide professional storage and usage guidelines, but also innovate and optimize product formulations to significantly enhance the stability of magnetic beads, ensuring their good dispersibility and activity in various environments.
In response to cost issues, we optimize production processes and integrate upstream and downstream resources to ensure high-quality products while minimizing prices, making it easier for more customers to use our products and promoting the development of our work.
In terms of cell function protection, our products have been extensively validated through experiments to minimize interference with normal physiological functions of cells, ensuring that the cells obtained during cell isolation and purification can maintain their original biological characteristics, providing a solid guarantee for subsequent experimental research.
Our immune magnetic beads
Shanghai Taoyu serves as a global manufacturer of diagnostic reagents, focusing on the sales of core raw materials for diagnostic reagent products. Shanghai Taoyu has advanced diagnostic microspheres, including immunoassay, immunochromatography, chemiluminescence, gene sequencing nucleic acid extraction, and four types of high-quality microsphere magnetic beads. We can provide high-quality and reliable core raw materials for global diagnostic reagent companies, hospitals, universities, and more. So far, there are more than 600 global partners, including a series of microspheres with any size and uniform particle size in the range of 20 nanometers to 1000 micrometers.
The products include carboxyl microspheres, polystyrene microspheres, fluorescent microspheres, time-resolved fluorescent microspheres, colored microspheres, magnetic microspheres, silica magnetic beads, PMMA microspheres, photo diffusion microspheres, liquid crystal spacer microspheres, microspheres for pore forming agents, standard particles, and polymer reverse phase chromatography fillers.
The performance of the products has reached or even exceeded that of similar products from well-known brands. Shanghai Taoyu looks forward to working with you to create a better future together!
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