Alkaline Phosphatase Substrates

Alkaline phosphatase (AP) substrates are used to facilitate the detection of protein targets in applications such as immunohistochemistry, western blotting, and ELISA. Some of the most widely used compounds include BCIP/NBT (5-Bromo-4-chloro-3-indolyl phosphate along with nitro blue tetrazolium), pNPP (para-Nitrophenylphosphate), and Fast Red. These substrates produce a detectable color change when added to alkaline phosphatase labels, typically conjugated to antibodies. When choosing a proper AP substrate, consider the colors present in the final staining to ensure easy differentiation.