1. Estimation of carbohydrate by Nelsons’s Method II Cupric ions are reduced by sugars to cuprous ions, which quantitatively reduce phosphomolybdic acid to a blue complex. Gluconic acid + Cu + + Cu² + + Cu + + Cu² + PMA Molybdenum (Blue Complex)

2. Materials 1. Alkaline copper reagent. 2. Phosphomolybdic acid reagent. 3. Standard glucose solution containing 1mg/ml. 4. Glucose solution of unknown strength( 30- 70 μg/ml). 5. Colorimeter or spectrophotometer.

3. Glucose (ml) 0 0.25 0.5 0.75 1 1.5 2 2 Tube # Blank 1 2 3 4 5 6 unk. D. W. (ml) 2 1.75 1.5 1.25 1 0.5 0 0 Alkaline Cu 2 2 2 2 2 2 2 2 Reagent (ml) 60 30 15 45 5 10 20 2535 40 50 55 8 min. COOL PMA 2 2 2 2 2 2 2 2 Reagent (ml) Shake Well 2 min. D. W. (ml) 4 4 4 4 4 4 4 4 Read the Optical Density at 630 nm

4. Results Samar A. Damiati