Fluorescence imaging proposes a convenient visualization method for the analysis of sialic acids. CD BioGlyco has developed various Strategies to analyze sialic acids using fluorescence imaging.

Sialic Acids

Sialic acids, also known as N-acetyl neuraminic acid, include a family of 9-carbon acidic monosaccharides, and usually are located at the terminal end of the glycan chains on the cell surface. Changes in the level of sialic acid expression on the cell surface are closely related to the development of cancer, as high expression of sialic acids usually is found on the surface of tumor cells. Therefore, the detection of sialic acid on the cell surface, especially in situ analysis, is of great significance to the diagnosis and therapy of cancer.

The Cases of Sialic Acid Fluorescent Image

Gold nanoparticles (AuNPs) are particularly attractive in cellular sensing due to their good biocompatibility and ease of functionalization. Therefore, scientists design a novel nanoprobe by combining the quenching ability of AuNPs on the fluorescence of the dansyl group with the recognition ability of the boronic group to sialic acid, which could be prepared by assembling 3-(dansylamino)phenylboronic acid (DAPB) on polysialic acid (PSA) embedded AuNPs (PSA-AuNPs). Due to the competitive binding of DAPB with cell surface SA, the immobilized DAPB is released in the presence of sialic acid-abundant cells. Thus, the fluorescence of DAPB on the sialic acid-abundant cell surface could be turned on, providing a visualization method for in situ imaging of sialic acid on the cell surface.

Scientists have synthesized molecularly imprinted polymers (MIP), labeled with fluorescent organic dyes or QDs, for selectively targeting and imaging sialylated glycosylation sites on/in human keratinocytes. The MIP protocol is more advantageous because it is simple and does not require primary and secondary antibodies. Furthermore, MIPs are not cytotoxic and are used for live-cell labeling and imaging.

Fig.1 The fluorescent images of sialic acid on the cell surface. (Qian, 2015)

Our Services

CD BioGlyco provides sialic acid fluorescent images, including but not limited to:

• We prepare DAPB functionalized PSA-AuNPs for in situ imaging and fluorescence quantification of sialic acid on the cell surface through the competitive binding of DAPB to PSA-AuNPs and sialic acid on the cell surface.
• We have synthesized fluorescently labeled molecularly imprinted polymers for imaging of human keratinocytes to localize and quantify hyaluronan and sialylation moieties on and in the cells.
• According to the characteristics of intracellular or in vivo sialylated glycans, we have designed and synthesized a novel sialic acid-imprinted conjugated polymer nanoprobe with two-photon fluorescent properties, which exhibits specific recognition ability to the target sialic acid and has been used for monitoring intracellular sialylated glycans levels selectively.
• We provide the synthesis of polymer chain wound nanoclusters for fast targeting and mapping of sialic acid under the fluorescent microscope.
• We also design a two-step fluorescence imaging/SERS labeling strategy for live-cell profiling of sialic acids.

Advantages of Us

• Various methods of fluorescence imaging
• Detailed analysis of sialic acid on the cell surface
• High efficiency and high sensitivity
• One-stop analysis service

CD BioGlyco is dedicated to providing high-quality analysis services of sialic acid using fluorescence imaging. If you are interested in our services, please contact us for more detailed information.

Reference:

1. Qian, R.; et al. Fluorescence imaging for in situ detection of cell surface sialic acid by competitive binding of 3-(dansylamino) phenylboronic acid. Analytica Chimica Acta. 2015, 894: 85-90.