Determination of adenosine triphosphate in yeast and blood

A method is described for the determination of ATP in yeast and blood, in which use is made of the decomposition of ATP by myosin adenosinetriphosphatase. ATP is extracted without injury by one minute's boiling at pH 2.5 to 3. Yeast extracts contain myokinase. To destroy this enzyme they are treated with 0.1% H2O2 at 60°C for 4 minutes and excess H2O2 is removed by a drop of dilute laked blood. The myosin test is then applied to the treated extract. Blood extracts do not contain myokinase. Fresh pressed yeast contains about 2 μM ATP per g, human blood contains 1−1.5 μM ATP/ml