In the alkaline phosphatase assay, you will you be monitoring the formation of product by measuring the absorbance of the solution using a spectrophotometer. Why are you monitoring the formation of product at a pH of 9 and a wavelength of 400nm. A. At pH 9, the product, p-nitrophenol, will be ionized, the solution will appear yellow in color, and thus can be monitored at the wavelength of maximum absorption for the phenolate ion which is 400nm.
B. At pH 9, the product, p-nitrophenol, will be ionized and colorless
C. At pH 9, the product, p-nitrophenol, will be un-ionized and yellow in color