Custom Oligonucleotides-Fluorescent Conjugation Service

As an expert in nucleic acid chemistry, Creative Biolabs has strong bioconjugation expertise and has successfully created complex labeled oligonucleotides. We offer custom oligonucleotide-fluorescent conjugates services to maximize value for our customers. At Creative Biolabs, the final conjugate is accompanied by a variety of assays to ensure that the product is well characterized and has the specified purity.

Oligonucleotides-Fluorescent Conjugation Services

In general, fluorescein-labeled oligonucleotides are synthesized as DNA or RNA probes. Fluorescently labeled oligonucleotide probes have many advantages, such as high sensitivity, high specificity, and low toxicity. High-sensitivity fluorescent detection and quantification systems rely on the flexibility of dye-labeling technology. At Creative Biolabs, we offer a variety of labeled oligonucleotides using a variety of fluorescent dyes or newly developed alternatives.

Fig. 1 Fluorescence labeling of nucleic acids.

Fluorescent Small Molecule

Small-molecule fluorophores are seen as crucial tools in chemical biology. They are widely used in experiments such as macromolecular labeling, cell staining, ion indicators, and enzyme substrates. Notably, these probes play a vital role in the detection, localization, or quantification of target DNA sequences in cells and other biological systems. A key advantage of synthetic fluorophores over other fluorophore types is the ability to use chemistry to control the properties of the fluorophore and direct the location of the fluorophore. Furthermore, the application of modern synthetic organic chemistry strategies is beneficial for tuning chemical structures to obtain probes for specific biological experiments.

Fluorescent Protein

In recent years, fluorescent proteins (FPs) have gradually become the focus of research in biochemistry. Imaging FPs in live cells is an important tool for studying cell biology and physiology. In addition, FPs, such as green FP (GFP), have been demonstrated to be involved in various biological studies. In fact, FPs can serve as universal gene-encoded markers for tracking proteins, organelles, or whole cells. Importantly, FPs are the basis for building sensors that are critical in visualizing ever-growing biochemical events in cells and tissues. For example, strategies for DNA visualization are mainly based on artificial genetic constructs that express specific DNA-binding peptides and proteins fused with FPs in cells.

Fig. 2 Applications of GFP-like proteins.²

Quantum Dots (QDs)

Semiconductor nanoparticles, especially QDs, are attractive alternatives to organic fluorophores. QDs are tiny particles or nanocrystals of a few nanometers in size with optical and electronic properties that differ from larger particles. One of the most obvious properties is that nanocrystals can produce unique colors determined by particle size. Potential applications of QDs include single-photon sources, quantum computing, cell biology research, microscopy, and medical imaging. Studies have shown that QD-DNA conjugates and high-sensitivity fluorescent imaging techniques are effective for visualizing gene transport across living cell membranes.

Oligonucleotides-Fluorescent Conjugates Strategies

The incorporation of fluorescent dyes into oligonucleotides mainly relies on two methods: direct oligonucleotide labeling in chemical synthesis and post-synthesis fluorescent oligonucleotide conjugation. In the first method, the attachment of fluorescent dyes to oligonucleotides is achieved by chemical methods. Direct oligonucleotide labeling with dyes can be used for 5', internal, and 3' labeling during chemical synthesis. The final product was purified by high-performance liquid chromatography (HPLC). In the second method, the attachment of fluorescent dyes to oligonucleotides can be achieved by using activating dyes with oligo containing functional groups. The functionalized oligonucleotides are then purified by HPLC and then conjugated to activating dyes by suitable cross-linking chemistry. After conjugation, a second HPLC was used to remove the unconjugated dye.

With extensive experience and an advanced platform, Creative Biolabs is confident to provide customized oligonucleotide-fluorescent conjugation services. Our oligonucleotide coupling services allow molecules, such as fluorescent small molecules and FPs, to be incorporated into DNA and RNA probes. If you are interested in our coupling services, please feel free to contact us for more details.