Used in bioconjugation and pharmaceutical research to introduce polyethylene glycol (PEG) spacers between a drug molecule and a targeting agent. The t-Boc protected amine allows for controlled deprotection and subsequent coupling to carboxylic acid-containing compounds. The PEG10 chain provides water solubility, reduces immunogenicity, and increases circulation time in vivo. The terminal alcohol group can be further modified to attach payloads such as fluorescent dyes, peptides, or small molecule drugs. Commonly used in the synthesis of antibody-drug conjugates (ADCs) and targeted therapeutics where a long, flexible linker is required for optimal binding and activity.