Quanta BioDesign’s building blocks and protected linkers enable SuperHydrophilic™ constructs and peptide modifications via our world-famous dPEG® products. Our simple-to-use products transform hydrophobic peptides into hydrophilic products. Moreover, the single molecular weight, discrete-length PEG chain (i.e., dPEG®) simplifies peptide analysis compared to dispersed PEG linkers that contain a range of PEG chain lengths and molecular weights.
We designed these compounds to work in solid-phase and solution-phase peptide synthesis without modification to existing protocols and for other applications where one end of the dPEG® spacer must be protected while the other end reacts. We offer Fmoc-, Cbz-, and boc- (t-boc-) protected linkers and spacers. Moreover, we offer novel constructs that facilitate the easy incorporation of hydrophilic biotin spacers into a growing peptide chain.
We invite you to review our products and see how we have conveniently designed chemistry into biology for powerful biotechnology and life sciences applications. However, if you want to jump to a specific group of products, please click the links below, and we’ll take you there.
Fmoc-protected Building Blocks
- N-Fmoc-amido-dPEG®x-acid
- N-Fmoc-amido-dPEG®x-NHS ester
- N-Fmoc-amido-dPEG®x-TFP ester
- N-Fmoc-Lys-(dPEG®x-biotin)-OH (acid)
CBZ- and t-boc-protected amino-dPEG®x-acid Building Blocks
Other dPEG® Building Blocks and Protected Linkers
Fmoc-Protected Building Blocks for Solid-Phase Peptide Synthesis
Fmoc-protected amino acids are popular reagents in solid-phase peptide synthesis. By design, our Fmoc-N-amido-dPEG®x acids and active esters incorporate directly into solid-phase peptide synthesis with no modification to existing protocols. Furthermore, these protected linkers work in solution-phase synthesis just like protected amino acids. Try them today and discover the dPEG® difference!
Fmoc-N-amido-dPEG®x-acid

Fmoc-protected amino-dPEG®x-acid products can be incorporated at either end or in the middle of a peptide chain or added to an amine-functionalized amino acid side chain.
Incorporating dPEG® linkers and spacers into peptides adds hydrodynamic volume, increases hydrophilicity, and decreases or eliminates immunogenicity.
These linkers are available in ten (10) different sizes from dPEG®2 to dPEG®48 (as a dPEG®24-amido-dPEG®24-acid) to cover almost every customer need.
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Fmoc-N-amido-dPEG®x-NHS ester

Fmoc-N-amido-dPEG®x-NHS ester products have all the benefits of our Fmoc-N-amido-dPEG®x-acid products; Preactivating the carboxyl terminus with N-hydroxysuccinimide (NHS) simplifies couplings to free amines.
Available in three highly popular linker lengths: dPEG®4, dPEG®8, and dPEG®12.
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Fmoc-N-amido-dPEG®x-TFP ester

Fmoc-N-amido-dPEG®x-TFP ester products have all the benefits of our Fmoc-N-amido-dPEG®x-acid products and the same reactivity as our Fmoc-N-amido-dPEG®x-NHS ester products.
TFP esters react with amines like NHS esters, are more resistant to hydrolysis than NHS esters, have higher selectivity than NHS esters in solution, and may provide superior reactivity with amines for challenging conjugations.
Available in five (5) different lengths from dPEG®4 to dPEG®36.
Click this link to see all of our Fmoc-N-amido-dPEG®x-TFP ester products.
To learn more about TFP esters as an alternative to NHS esters, please click here.
Fmoc-N-amido-Lys(dPEG®x-biotin)-OH (acid)

A unique peptide building block from Quanta BioDesign!
This product incorporates a flexible, hydrophilic dPEG®-biotin group on the side chain of Fmoc-protected lysine.
The lysine can be added anywhere along the peptide chain, although the N-terminus is the preferred location. The resulting product is a biotinylated peptide that is useful for a variety of applications that take advantage of the strong binding between biotin and (strept)avidin.
The hydrophilic dPEG® spacer improves the hydrophilicity and reduces the immunogenicity of the final peptide product.
Two linker sizes (4 and 12) are available and ready for use.
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CBZ- and t-boc-protected amino-dPEG®x-acid Building Blocks
Benzyl carbamates (CBZ-protected amines) and tert-butyl carbamates (BOC-protected amines) are useful in solution-phase peptide synthesis and many other synthetic reactions. They are also among the most popular amine protecting groups currently used. The protecting groups shield the amine from reacting while the carboxyl end of the dPEG® linker is free to react with amines to form amide bonds.
Our dPEG® linkers cover a broad range of chain lengths. Each high-purity product contains a single molecular weight PEG with a discrete chain length, thus simplifying the analysis of the resulting conjugate. We invite you to try our products today and discover the dPEG® difference.
t-boc-N-amido-dPEG®x-acid

The BOC group is the most widely used protecting group for amines.
It is stable to base but cleaves easily and cleanly with trifluoroacetic acid (TFA), yielding only CO2 and tert-butanol or isobutylene as by-products.
We offer five (5) high-purity products ranging from dPEG®4 to dPEG®36.
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CBZ-N-amido-dPEG®x-acid

The CBZ group provides stable protection for amines under a wide variety of conditions.
CBZ groups deprotect cleanly under various mild conditions. A common method of cleaving the CBZ protecting group is hydrogenation with a metal catalyst such as palladium on carbon. However, many different deprotection methods are published.
We offer seven (7) products ranging in size from dPEG®4 to dPEG®24-amido-dPEG®24 (i.e., a dPEG®48).
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Other dPEG® Building Blocks and Protected Linkers
Methoxytrityl-S-dPEG®x-acid

These SuperHydrophilic building blocks are tools that add a dPEG® linker with a terminal thiol to an amino group. They can be used at the N-termini of peptides or the N-side chains of amino acid residues within the chain.
The resulting conjugate can modify physical properties or introduce a spacer end group.
The methoxytrityl group cleaves with TFA in the presence of a scavenger such as TES or TIS.
Three sizes of dPEG® linker are available: dPEG®4, dPEG®8, and dPEG®12.
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Amino-dPEG®12-ODMT for Nucleic Acids, Peptides, and SuperHydrophilic Constructs

Build better aptamers by incorporating a discrete PEG (dPEG®) spacer into oligonucleotides.
Modify the side chains of acidic amino acids to increase hydrophilicity and add hydrodynamic volume.
Use Amino-dPEG®12-ODMT, product number 10342, in macromolecular constructs to add defined, SuperHydrophilic spacers to the macromolecular architecture.
After reacting the amine end of the dPEG® linker, the dimethoxytrityl protecting group removes easily under mild conditions, exposing the terminal alcohol.
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