Chemical examination of urine by wet method

Previously, color and precipitation reactions carried out in the so-called "wet way" (in test tubes) were used to detect pathological components of urine. Their principles are summarized in the table:

Principles of determination of pathological components of urine using color and precipitation reactions carried out in test tubes

Analyt	Principle of reaction	Individual exams
Protein	protein denaturation	trial with sulfosalicylic acid Heller's test (with concentrated HNO3) boiling test
Hemoglobin	pseudoperoxidase activity of heme iron – catalyzes the oxidation of suitable chromogens to colored products hydrogen peroxide	Heitz-Boyer test (oxidation of reduced phenolphthalein) benzidine test (oxidation of o-tolidine or tetramethylbenzidine)
Glucose	non-specific tests based on the reducing properties of glucose	Fehling test (reduction of Cu2+) Benedict test (reduction of Cu2+) Nylander test (reduction of Bi3+)
Ketone bodies	reaction with sodium nitroprusside in an alkaline medium to form a purple complex	Legal's reaction Lestradet's test
Bilirubin	oxidation of bilirubin to green biliverdin or blue bilicyanin	Rosin test (with iodine) Gmelin test (with concentrated HNO3)
Urobilinogen	reaction of urobilinogen with 4-dimethylaminobenzaldehyde in an acidic environment to form a colored condensation product	Ehrlich test

Links

References

• SCHNEIDERKA, Petr, et al. Kapitoly z klinické biochemie. 2. vydání. Praha : Karolinum, 2004. 365 s. ISBN 80-246-0678-X.