CD BioGlyco has developed a highly specialized Glycoengineering Platform and systematic solutions for site-specific antibody conjugation with Alexa Fluor 488.
Alexa Fluor 488 dye is an important cell tracer and a reactive dye for labeling aldehydes or ketones in polysaccharides or antibodies. Alexa Fluor 488 is a bright green fluorescent dye with an excitation spectrum well suited to the 488 nm laser line. Alexa Fluor 488 dye is used for stable signal generation in imaging and flow cytometry. Importantly, it is water-soluble and pH-insensitive (pH 4-10). In addition, Alexa Fluor 488 dye produces protein conjugates that are brighter and more photostable than fluorescein conjugates.
Fig.1 Chemical structure of Alexa Fluor 488. (PubChem)
Currently, most antibody conjugates are constructed by traditional chemical methods, such as acylation of lysine residues and amines at the N-terminus, and thiol alkylation of cysteine residues. However, these non-site-specific conjugates suffer from numerous drawbacks, such as the generation of heterogeneous mixtures and positional isomers, and poor reproducibility.
This traditional strategy also increases the complexity of conjugate characterization. In one aspect, the antibody itself consists of various post-translational modifications, such as deamidation, oxidation, glycosylation, or other reactive metabolites. Therefore, the analysis of antibody conjugates constructed by nonspecific methods is rather complicated. On the other hand, modification sites are easily detected.
Fig.2 Site-specific labeling with aminooxy-Alexa Fluor 488 of human α-lactalbumin with a 17–amino acid C-terminal extension. (Mercer, et al., 2011)
To overcome nonspecific conjugation barriers, it is important to develop site-specific methods for modifying antibodies that yield homogeneous and well-defined conjugates without compromising the biological activity of the antibody conjugates.
CD BioGlyco offers a method for the specific conjugation of antibodies labeled with Alexa Fluor 488. This technology specifically conjugates Alexa Fluor 488 to conserved N-linked glycosylation sites on the CH2 domain of each heavy chain of the Fc region. This technique is suitable for labeling a variety of IgGs using the fluorescent label Alexa Fluor 488. After the reaction is completed, the antibody-Alexa Fluor 488 conjugate can be used for various types of experiments such as western blot and enzyme-linked immunosorbent assay.
CD BioGlyco has first-class technology and well-trained technicians, and provides customers with comprehensive and reliable Site-Specific Antibody Conjugation Service. If you are interested in our services, please contact us for more detailed information.
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