Succinimidyl 6-hydrazinonicotinate acetone hydrazone (SANH; S-HyNic) is a heterobifunctional linker used
for introducing protected hydrazinonicotinimide functional groups into proteins, peptides, surfaces and other
primary amine containing molecules via its reactive N-hydroxysuccinimide ester terminus. Upon
deprotection of the hydrazone functionality under acidic or neutral pH (4.5-7.4), the liberated hydrazine group
can then react with aldehydes and ketones to form stable bonds. SANH has also been used extensively for
the labeling of biomolecules with the SPECT imaging isotope, 99mTc [1-4].