Biotin-PEG12-acid is widely used in bioconjugation and labeling applications due to its biotin moiety and long polyethylene glycol (PEG) spacer. The biotin group allows for strong and specific binding with avidin or streptavidin, making it valuable in immunoassays, protein purification, and diagnostic assays. The PEG12 spacer enhances solubility, reduces steric hindrance, and improves the accessibility of the biotin group, ensuring efficient binding. This compound is also employed in the development of targeted drug delivery systems, where biotinylated molecules can be directed to specific cells or tissues. Additionally, it is utilized in surface modification for biosensors and biochips, providing a stable and functional interface for biomolecular interactions. Its versatility makes it a key reagent in various biochemical and biomedical research applications.