The microtiter plate provided in this kit has been pre-coated with an antibody specific to ALDH. Standards or samples are then added to the appropriate microtiter plate wells with a Horseradish Peroxidase (HRP) -conjugated antibody preparation specific for ALDH and incubated. Then substrate solutions are added to each well. The enzyme-substrate reaction is terminated by the addition of a sulphuric acid solution and the color change is measured spectrophotometrically at a wavelength of 450 nm +/-