BCN-OH (endo-9-Hydroxymethylbicyclo[6.1.0]non-4-yne) is a mitochondrial probe based on the lyophilic bidentate bicyclic ligand BCN and is a control reagent for BCN-TPP. The TPP group is a reactive sulfenic acid probe that targets mitochondria. BCN-TPP is known to affect mitochondrial energy, causing a sharp decrease in basal respiration, causing it to exhibit faster reaction kinetics with sulfonated proteins. BCN-OH does not contain hydrophobic triphenylphosphonium (TPP) ions. Using BCN-OH as a control allows the TPP group to be safely introduced when designing sulfenic acid traps^[1].