Fehling’s Test: Procedure

The procedure for Fehling’s test is:

  1. Put approximately 1 mL of Fehling’s A and 1 mL of Fehling’s B in a clean dry test tube.

  2. Add 2-3 drops of the liquid sample into the test tube.

  3. Heat the content of the test tube for about 2 minutes in a heated water bath.

  4. Formation of a brick-red precipitate of cuprous oxide indicates the presence of a reducing sugar.

Figure 1 - Fehling's test procedure for detecting the presence of reducing sugars in a sample.