This compound is widely used in bioconjugation and chemical biology due to its unique functional groups. The pyridyldithio moiety allows for selective conjugation with thiol-containing molecules, making it valuable for creating stable disulfide bonds in protein labeling, drug delivery systems, and antibody-drug conjugates. The PEG4 spacer enhances solubility and reduces steric hindrance, improving the efficiency of conjugation reactions. Additionally, the propargyl group enables click chemistry, particularly copper-catalyzed azide-alkyne cycloaddition (CuAAC), facilitating the attachment of azide-containing molecules. This versatility makes it a critical tool in the development of targeted therapeutics, diagnostic probes, and biomaterials.