1. No significant differences were noted between the electrophoretic mobilities of unground cholesterol crystallized from alcohol, acetone, or the melted state.
2. On grinding with ice at –10°C. the mobility drops to less than half (at pH 5.8) that observed in the unground state. This equilibrium condition is reached after 50 minutes grinding. Cholesterol crystals from alcohol or acetone behave identically throughout the course of this change.
3. When cholesterol crystals which have been ground with ice are dried in vacuo at room temperature they revert to the mobility of unground cholesterol. The cause of this phenomenon is discussed.
4. Both ground and unground cholesterol have an isoelectric point near pH 3.0, even after crystallization from the melted state.