Laboratorio experimental - Lípidos U.N. Sede Manizales

Lipid Practice Overview

Introduction to Lipid Experiment

• The practice begins with the preparation of lipid samples using a test tube rack and four test tubes.

• Required materials include distilled water, vegetable oil, pasteurized milk, Sudan III indicator, and melted butter.

Preparing Negative Control

• The first step involves preparing a negative control using approximately 23 ml of distilled water.

• Drops of Sudan III are added to the distilled water; the resulting reddish color indicates no lipids present.

Testing Positive Control

• For the positive control, vegetable oil is used instead of distilled water in equal amounts.

• After adding five drops of Sudan III and mixing, small bubbles appear indicating a positive reaction for lipids.

Testing Milk and Butter Samples

Sample Collection from Milk

• A syringe is used to extract about 2 ml of milk for testing, matching the amount used for controls.

Observations with Milk

• Upon adding Sudan III to the milk sample, small bubbles form on the surface indicating lipid presence but in lower concentration compared to oil.

Testing Melted Butter

• Melted butter is tested similarly by adding five drops of Sudan III after ensuring it is fully melted.