Ethyl-PEG4-alcohol（Cat No.:I044725）is a linear polyethylene glycol (PEG) derivative consisting of an ethyl group at one end and a terminal hydroxyl (–OH) group at the other, separated by four ethylene glycol units (PEG4). This molecule offers excellent water solubility, flexibility, and low immunogenicity, making it ideal for biomedical and chemical applications. The hydroxyl group provides a reactive handle for further functionalization, such as esterification or ether formation. Ethyl-PEG4-alcohol is commonly used as a spacer, linker, or solubilizing agent in drug delivery systems, bioconjugation, polymer synthesis, and surface modification strategies.