SHS is a group of water soluble iron oxide nanocrystals with amphiphilic polymer coating. Their surface functional group is streptavidin. The zeta potential of SHS is from -20mV to -40mV. Their organic layers consist of a monolayer of oleic acid and a monolayer of amphiphilic polymer. The thickness of the total organic layers is about 4 nm. The hydrodynamic size of the nanocrystals is about 8-10 nm larger than their inorganic core size measured by TEM. The streptavidin molecules are linked to polymer. SHS is very stable in most buffer solutions.
SHS can be conjugated to biotinylated molecules such as protein, DNA and peptide. For the reactions to link biotinylated molecules onto SHS, it is necessary that only one biotin be linked on each biomolecule. Otherwise, the nanocrystals will aggregate. Please refer to our Biotinylated Protocol to tag one biotin on each antibody.