NH2-PEG-NH2 (MW 10000) is a polyethylene glycol derivative featuring two primary amine groups. These amine groups can quickly react with activated carboxylic acids or carboxyl groups (e.g., NHS esters) to form stable amide bonds. The pegylation of NH2-PEG-NH2 enhances solubility and stability while reducing the immunogenicity of peptides and proteins, making it primarily used for modifying proteins, peptides, and other substances.