Iodo-PEG-Acid is a chemical compound that belongs to the class of polyethylene glycol (PEG) derivatives. The functional groups in Iodo-PEG-Acid include an iodine atom, a carboxylic acid group, and a PEG moiety. The introduction of these functional groups enhances the water solubility and stability of the compound, making it an ideal candidate for use in pharmaceutical research and development. Specifically, Iodo-PEG-Acid is often used as a linker molecule for the conjugation of drugs and other biomolecules, as it can bind to various biomolecules through its carboxylic acid group and can be easily modified with additional functional groups. Additionally, the iodine atom in Iodo-PEG-Acid can serve as a useful radiolabel for imaging studies.