Proposal for dyes with PEG linkers and fluorescent dyes.

The application of PEG linkers can have the following effects

The insertion of spacers ensures sufficient distance between each functional site and increases reactivity with proteins, cells and other macromolecules.

Compared to alkyl linkers, non-specific adsorption and aggregation are expected to be reduced.

Adding a PEG linker improves both hydrophilic and lipophilic properties and increases solubility in water and organic solvents, reducing difficulties such as dissolution residue and turbidity.

Most commercially available dyes are limited to carboxylic acids, active esters such as NHS and maleimides, but can be changed to various end-functional groups such as amino groups, azides and alkynes via PEG linkers.

*Spacers of the optimum length for each evaluation system, from PEG repeat units n = 3 to 50 or more, are available from us.



Shinsei Chemical has extensive experience in the synthesis of fluorescent dyes, and has the technology and experience in the synthesis of dyes directly bonded with PEG linkers without amide bonding or similar.



We have succeeded for the first time in synthesising a structure in which PEG is directly bonded to a Cyanine-based fluorescent dye.

This achievement has opened up the possibility of attaching PEGs of any length directly to cyanine-based fluorescent dyes without the need for amide bonding.

We are also investigating the binding of longer PEG chains and the synthesis of end structures other than carboxylic acids. Please feel free to contact us for more information, as we can accommodate your desired structure at a price range different from that of general contract synthesis.



PEG linkers can be easily inserted from commercially available fluorescent dyes (terminal carboxylic acids, NHS active esters, isocyanates, isothiocyanates, etc.), showing a significant improvement in hydrophilicity.

Some of the synthesis results to date are presented below.

Click here for other fluorescent dyes.