BIOTIN HPDP is a bicyclic biotin ring structure, attached to the 1,6-diaminohexane linkage group of the biotin pentanoic acid side chain, and is also the terminal sulfhydryl reactive group, the terminal pyridinium disulfide group can be involved in the free sulfhydryl group in the formation of disulfide bonds with proteins, other molecules, release of the reaction of the pyridinium-2-thione, the product can be modified molecules to better bind to the antibiotic protein or streptavidin anti-biotin probes. protein or streptavidin probe.