BCIP/NBT AP Substrate Kit forms an indigo, heat stable reaction product that can be dehydrated, cleared, and permanently mounted. This chromogen can be used singly or in combination with other alkaline phosphatase or peroxidase substrates for multiple label applications. This substrate can also be used for developing blots or for in situ hybridization. At 20-30 minute development times, the sensitivity of this substrate is equivalent to the other alkaline phosphatase substrates. However, BCIP/NBT will continue to develop from several hours to overnight making it one of the most sensitive chromogenic substrates. This kit contains stock solutions in convenient dropper bottles.