Used extensively in bioconjugation and crosslinking applications, it facilitates the attachment of biomolecules such as proteins, peptides, and antibodies to other entities like nanoparticles or surfaces. The NHS ester group reacts efficiently with primary amines, forming stable amide bonds, while the SPDP group enables thiol-reactive conjugation, allowing for the formation of disulfide bonds. This dual functionality makes it a versatile tool in drug delivery systems, where it can be used to create targeted therapeutic conjugates. Additionally, it is employed in the development of diagnostic assays, enabling the labeling of biomolecules for detection and analysis. Its PEG spacer enhances solubility and reduces steric hindrance, improving the efficiency of conjugation reactions.