Urine Tests Explained: Detecting Sugar, Ketones, and Proteins

Urine Tests Explained: Detecting Sugar, Ketones, and Proteins

Write the tests to identify the following in urine Sugar, Ketone bodies, Proteins
Answer:

Test to detect sugar in urine:

1. Benedict’s test

• Used to detect reducing sugar in the urine
• Enediol forms of sugar reduce cupric ions of copper sulfate to cuprous ions
• The color of the precipitate indicates the approximate amount of glucose present

2. Glucose oxidase test

• Glucose oxidase oxidizes glucose to liberate hydrogen peroxide
• This is converted to nascent oxygen
• The compound O-diansidine combines with nascent oxygen to form a colored complex

Test to detect ketone bodies in urine

1. Rothera’s test

• In this test, nitroprusside reacts with the keto group of ketone bodies
• Results in the formation of the purple ring

Test to detect proteins in urine:

1. Sulfosalicyclic acid test

• On reacting with Sulfosalicyclic acid, proteins get precipitated as protein-sulfosalicylic

2. Heat coagulation test

• Used to detect Albumin & globulin
• Based on the principle of denaturation of proteins followed by coagulation