Biotin PEG acid is widely used in bioconjugation and labeling applications due to its ability to link biotin to other molecules or surfaces. It is commonly employed in the preparation of biotinylated probes for use in immunoassays, such as ELISA, where it enhances detection sensitivity. The PEG spacer provides flexibility and reduces steric hindrance, improving binding efficiency with streptavidin or avidin. It is also utilized in the development of drug delivery systems, where biotinylation enables targeted delivery to specific cells or tissues. Additionally, Biotin PEG acid is used in surface modification of nanoparticles and biomaterials to facilitate functionalization for diagnostic or therapeutic purposes. Its versatility makes it a valuable tool in biomedical research and biotechnological applications.