The MaxDiscovery™ Alkaline Phosphatase ELISA Kit is an enzyme immunoassay that analyzes the quantity of alkaline phosphatase in human cells, tissues, serum or urine. Alkaline phosphatase is a well known hydrolase enzyme responsible for removing phosphate groups from molecules including nucleotides, proteins and alkaloids. In humans, alkaline phosphatase is present in all tissues throughout the body, but is concentrated in the liver, bile duct, kidney, bone and placenta. The normal range of alkaline phosphatase is 44-147 IU/L. High alkaline phosphatase levels can show that the bile ducts are blocked. Levels are significantly higher in children and pregnant women. Also, elevated alkaline phosphatase indicates that there could be active bone deposition occurring as alkaline phosphatase is a by-product of osteoblast activity. Like most ELISA assays, the MaxDiscovery™ Alkaline Phosphatase ELISA Kit relies on a Horseradish Perioxidase (HRP) conjugated antibody and the TMB (3,3´,5,5´-tetramethylbenzidine) substrate. TMB is a chromogen that yields a blue color when oxidized with hydrogen peroxide (catalyzed by HRP) that has major absorbances at 370 nm and 652 nm. The color then changes to yellow with the addition of acid with maximum absorbance at 450 nm. The relative amount of alkaline phosphatase protein in the cells will be directly proportional to the amount of signal that is obtained at 450 nm. This kit contains materials for the extraction and quantitative detection of the alkaline phosphatase protein in cells, serum, tissues or urine.