The inherent fluorescent properties of nucleosides and nucleotides are limited and therefore require fluorescent labeling. Fluorescently labeled nucleosides and nucleotides are a key element in life science research and are effective tools for detecting specific nucleic acid sequences in molecular biology assays. They are biologically active and are usually detected and analyzed by incorporation into DNA or RNA sequences through the action of enzymes. The labeling of nucleosides and nucleotides can be divided into two categories: isotopic labeling and non-isotopic labeling. The isotope labeling method is simple and highly sensitive, but there are problems such as environmental pollution and radioactive waste disposal. Non-isotopic labeling has no radioactive contamination and can be stored for a long time.
Fig.1 Fluorescent labeling strategies. (Kricka & Fortina, 2009)
CD BioGlyco provides clients with high-quality fluorescent labeling services of nucleosides and nucleotides. We have two labeling methods: direct labeling and indirect labeling. Direct labeling is to directly bind fluorescein to nucleoside or pentose phosphate backbone covalently, or incorporate fluorescein-nucleoside triphosphate to label. And then directly detect the fluorescent signal after hybridization. The final product is purified by high-performance liquid chromatography (HPLC) to remove truncations, deletion mutation products, and non-fluorescently labeled nucleosides or nucleotides. Indirect labeling is achieved by first covalently attaching a second label to a nucleoside or nucleotide, which is then attached to a fluorescently labeled ligand conjugate.
Depending on the sequence of the nucleotides, we covalently attach the fluorescent dye to the nucleotides at specific points. This covalent bond is relatively stable and will not be broken under most biological conditions. In some cases, functional linkers are also introduced between the fluorescent dye and the nucleotide to minimize changes in the biological activity of the nucleotide. In general, we prefer fluorescent dyes that have high fluorescence quantum yields and retain the biological activity of unlabeled biomolecules based on your specific molecule.
We provide various types of fluorescent labeling dyes to help clients combine them with nucleosides or nucleotides. Our fluorescent dyes include but are not limited to coumarins, fluoresceins, rhodamines, and anthocyanins. Excitation maxima and emission maxima of some fluorescent dyes are shown here.
Fluorescence Name | Excitation Maxima (nm) | Emission Maxima (nm) |
Fluorescein | 495 | 519 |
Rhodamine Green | 505 | 535 |
Cascade Blue | 396 | 410 |
Alexa Fluor 488 | 495 | 519 |
Alexa Fluor 532 | 532 | 554 |
Alexa Fluor 555 | 555 | 565 |
Alexa Fluor 633 | 632 | 650 |
AMCA | 350 | 452 |
Cy2 | 489 | 506 |
Cy3 | 554 | 568 |
CY3.5 | 588 | 604 |
CY5 | 650 | 669 |
CY7 | 754 | 778 |
CD BioGlyco is a professional glycobiology company dedicated to helping clients solve difficulties and problems in glycobiology research. With the advanced Glyco™ Synthesis Platform, we provide clients with customized synthesis of Carbohydrates, Glycolipids, Glycopeptides, Glycoproteins, Glycoconjugates, etc. If you are interested in our services, please feel free to contact us.
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