You have isolated glycogen from animal tissues by dissolving the tissues in KOH and precipitating with Na₂SO₄ and ethyl alcohol. The glycogen was then redissolved in distilled water to a final volume of 10 mL for liver and 5 mL for muscle. To determine the amount of tissue glycogen, the glycogen was reacted with anthrone to yield a blue colored complex. The intensity of blue can be measured spectrophotometically. Darker blue means more glycogen.

You determined the abs. of a glycogen standard reacted with anthrone. The standard contained 10 µg/mL glycogen. The concentration of tissue glycogen can be determined by comparison with the standard. Use the Excel spreadsheet for your calculations and class data.

Here are sample data from other classes. The advantage of having several samples is that the data can be averaged to eliminate the question of an unusual sample or experimental error.