Benzyloxy carbonyl-PEG3-t-butyl ester linker contains two carboxylic acid that are protected by a benzyl and a t-butyl group. The two protecting group can be removed hemoselectively. Thus, the two acid group can be utilized in bioconjugation in a controlled fashion.
Axispharm offers 3000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.