Urobilinogen: this test is based on the Ehrlich reaction in which p-diethylamino benzaldehyde in conjunction with a color enhancer reacts with urobilinogen in a strongly acid medium to produce a pink-red color.

Bilirubin: The direct bilirubin and dichlorobenzene diazonium produce fuchsia azo dyes in a strongly acid medium.

Ketone: The acetoacetate and sodium nitroprusside cause a reaction in the alkaline medium, which produces a violet color.

Blood: Hemoglobin acts as a peroxidase. It can cause peroxidase to release neo-ecotypes oxide [O]. [O] oxidizes the indicator and causes the color change.

Protein: The test is based on the protein-error-of-indicators principle. An ion in the specific pH indicator attracted by cation on the protein molecule makes the indicator further ionized, which changes its color.

Nitrite: Nitrite in the urine and aromatic amino sulphanilamide are diazotized to form a diazonium compound. The diazonium compound reacting with tetrahydro benzo(h) quinolin 3-phenol causes the color change.

Leukocytes: Granulocyte leukocytes in urine contain esterase that catalyze the hydrolysis of the pyrrole amino acid ester to liberate 3-hydroxy-5-pheny pyrrole. This pyrrole reacting with diazonium forms a purple color.

Glucose: The glucose oxidized by glucose oxidase catalyzes the formation of glucuronic acid and peroxide hydrogen. Peroxide hydrogen releases neo-ecotypes oxide [O] under the function of peroxidase. [O] oxidizes iodide potassium, which causes the color change.

Specific Gravity: Electrolyte (M⁺X^-) in the form of salt in urine reacts with poly methyl vinyl ether and maleic acid (-COOH), which is a weak acid ionic exchanger. The reaction produces hydrogenous ionogen, which reacts with a pH indicator that causes the color change.

PH: Applied to acid alkali indicator method.