The Features of Oligonucleotide Fluorescein Labeling

Oligonucleotide fluorescent labeling is usually accomplished by inserting one or more fluorescent dyes directly into the synthetic sequence; or with reactive functional groups (e.g., phosphoryl, amino, or tectonic groups) are artificially labeled with reactive groups on the fluorescent dye molecule to complete the labeling. The fluorescent groups attached to the 5' end, the 3' end, the base end of the nucleoside, or the structure of the phosphate and ribose by covalent bonding. After completion of marking, the product needs to be purified for further use. The target DNA or RNA is analyzed by various forms of hybridization reactions with the target nucleic acid molecules, followed by relevant fluorescent probe detection techniques. Among the diagnostic tests relevant to the application of this strategy, fluorescence detection (e.g., fluorescent probe-based qPCR) is an extremely important class of technology.

Fig.1 The principle of operation of a fluorogenic molecular beacon. (Brylev, et al., 2021)

Oligonucleotide Fluorescein Labeling Services at CD BioGlyco

Fluorescein-based assays are being increasingly used in molecular analysis, and sequence-specific fluorescent-labeled probes are favored. CD BioGlyco provides design, synthesis, and purification of single fluorescently labeled probes and multiplexed fluorophore-labeled probes. Using this approach, specific detection and identification of a wide range of synthetic nucleic acid targets were achieved. This strategy provides accurate protein site amplification and genotyping results. Depending on the position of the marker, the fluorescein labeling of CD BioGlyco providing oligonucleotides mainly includes the following labels.

• Mark the oligonucleotides at the 5' end

• The final stage of the order of oligonucleotide synthesis links the phosphor amide containing the fluorescent group directly to the 5' end of the oligonucleotide.
• An amino alkane phosphor amide or other group is inserted at the 5' end of the oligonucleotide, and then the fluorescent group is attached to the above 5' amino group or another group without the protection group. This fluorescent group should have reactive groups such as isothiocyanate or N-hydroxysuccinimide ester (NHS) required for ligation.

• Mark the oligonucleotides at the 3' end

We synthesize oligonucleotides by attaching fluorescent dyes to a solid phase carrier and then in the form of dimethyl terephthalate (DMT) protection.

• Oligonucleotides are labeled at the base

Through a suitable group reaction, the fluorescent dye is attached to the amino or building functional group on the base. Generally, more than three carbon connecting arms keep the fluorescent dye away from the nucleotide and spatially do not hinder the hybridization or enzymatic catalytic process.

Fig.2 The process of fluorescein-labeling service. (CD BioGlyco)

Applications of Oligonucleotide Fluorescein Labeling

• Design of fluorescent probes for biological sample detection, such as heparin, chondroitin sulfate, etc.
• The fluorescein-labeled oligonucleotide can be used in molecular diagnosis and research.
• The fluorescein-labeled oligonucleotide can be used in nucleic acid testing and genotyping
• The fluorescein-labeled oligonucleotide is suitable for continuous monitoring of the polymerase chain reaction.

Advantages

• Fluorescein-labeled oligonucleotide with superior specificity, and high recognition ability.
• Our company is able to pay extra attention to the quality of services and strictly control every step of the way.

CD BioGlyco has focused on Carbohydrate Synthesis for many years. We provide effective design and analysis of labeling routes, to provide clients with the most convenient service. In addition, we provide other Fluorophore Modification services, such as Carboxyfluorescein (FAM) Labeling service, Tetrachlorofluorescein (TET) Labeling service, Hexachlorofluorescein (HEX) Labeling service, etc. Please feel free to contact us to learn more about the modification of oligonucleotide fluorophores.