This method is used for the determination and enumeration of Escherichia coli (E. coli) and coliform bacteria in sugar products by means of membrane filtration of dissolved sugar/sugar products and incubation of the membrane on agar plates or nutrient pads containing special chromogenic or fluorogenic substrates. These are hydrolysed by either coliform bacteria or E. coli and the colonies appear in different colours or the fluorescence of a colony can be visualised by exposure to UV-light at 366 nm. Chromogenic substrates which are hydrolysed by coliform bacteria are those that contain a dye bound to galactose (e.g. 6-chloro-3-indolyl-β-D-galactoside (Salmon-Gal) or 5-bromo-4-chloro-3-indolyl-β-D-galactoside (X-Gal) [1]). Chromogenic substrates which are hydrolysed by E. coli but not coliform bacteria are those containing a β-D-glucuronide (e.g. 5-bromo-4-chloro-3-indolyl-β-d-glucuronide (X-Gluc) [2] or 4-methylumbelliferyl-β-D-glucuronide [3]).