Photoclick cholesterol is a sterol lipid cholesterol analog that contains a clickable terminal alkyne moiety and a photoactivatable diaziridine group. Photoclick cholesterol has the ability to photoaffinity label the mitochondrial outer membrane transport protein (TSPO) and is able to specifically bind cholesterol to TSPO. However, using excessive amounts of Photoclick cholesterol will reduce the photolabeling of total mitochondrial proteins and TSPO.