DOTA-GA(tBu)4 is a protected bifunctional DOTA derivative that combines the 1,4,7,10-tetraazacyclododecane chelator framework with a glutaric-acid-derived conjugation handle. Four carboxyl functions are protected as tert-butyl esters, while one carboxyl group remains available for derivatization. The current Alan Scientific H1 is retained as DOTA-GA-tetra(tBu-ester) for URL continuity; the scientific body uses the normalized DOTA-GA(tBu)4 name.

This reagent is most useful before metal loading. It provides a route for attaching a DOTA-type chelator to an amine-containing molecule and then removing the tert-butyl groups to expose the carboxylate-rich coordination environment. For a complete peptide project, Alan Scientific can evaluate the chelator together with the intended sequence through our chelating-group and modified peptide synthesis service.

Product Information

Why the GA Handle Changes the Use Case

The glutaric-acid-derived side arm gives DOTA-GA(tBu)4 an additional conjugation handle beyond the macrocyclic chelator core. That handle is the reason this compound should not be treated as an interchangeable synonym for every protected DOTA reagent. We consider the attachment geometry, linker length and site of conjugation part of the final probe design because they can change accessibility of the metal complex in a peptide or biomolecule.

Protected Chelator First, Metal Complex Later

The tert-butyl esters reduce premature carboxylate reactivity during synthetic assembly. After conjugation, acid-mediated deprotection can expose the DOTA carboxylates required for strong metal coordination. The protected starting material is therefore a chelator precursor rather than a ready-to-use radiometal complex. Metal loading, radiochemical purity and biological performance belong to the downstream conjugate, not to this reagent alone.

DOTA-GA(tBu)4 vs DOTA-tris(tBu ester)

The related DOTA-tris(tBu ester) precursor has three tert-butyl-protected acetate arms and one free acetic-acid arm. DOTA-GA(tBu)4 uses a different bifunctional architecture with a GA-derived handle and four tert-butyl esters. Matching the correct scaffold to a published route matters more than selecting solely by the word “DOTA.”

Procurement and QC Considerations

Confirm CAS 306776-79-4, formula C35H64N4O10 and molecular weight 700.91 g/mol on the lot-specific COA. For conjugation work, the drawn structure and number of protected esters should be checked together with HPLC/MS identity. We also recommend protecting the material from unnecessary heat and moisture; public supplier records commonly specify dry handling and, for some products, cold storage.

Product Documents

A Safety Data Sheet (SDS / MSDS) is available for this product to support laboratory handling, storage and safety assessment.

📎 MSDS_DOTA-GA-tBu4_AS2120.pdf

Frequently Asked Questions

What is DOTA-GA(tBu)4 used for?

It is used as a protected bifunctional DOTA chelator precursor for conjugation to peptides and other amine-containing research molecules.

Can this protected reagent chelate a metal directly?

The tert-butyl-protected form is primarily a synthetic precursor. The protecting groups are normally removed before the final DOTA coordination environment is used for metal complexation.

Is DOTA-GA(tBu)4 the same as DOTA-tris(tBu ester)?

No. Their protecting-group counts and bifunctional side-arm architectures differ, so they should be selected according to the intended conjugation route.

Related Technical Resources

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