This chemical is primarily used in bioconjugation and labeling applications, particularly in the fields of biochemistry and molecular biology. It serves as a versatile linker for attaching biotin or biotin-like molecules to proteins, peptides, or other biomolecules. The PEG4 spacer enhances solubility and reduces steric hindrance, allowing for efficient binding and interaction with target molecules. The NHS ester groups enable covalent attachment to primary amines, making it suitable for modifying antibodies, enzymes, or other proteins for use in assays, diagnostics, or drug delivery systems. Its application is especially valuable in techniques like pull-down assays, affinity purification, and imaging studies where biotin-streptavidin interactions are utilized.