Heller's test

Heller's test is a chemical test that shows that strong acids cause the denaturation of precipitated proteins. Concentrated nitric acid is added to a protein solution from the side of the test tube to form two layers. A white ring appears between the two layers if the test is positive.^[1] Heller's test is commonly used to test for the presence of proteins in urine.^[2] This test was discovered by the Austrian Chemist, Johann Florian Heller (1813-1871).