Ethanol-induced formation of solid calcium phosphates

Conventional transmission electron microscopy requires an effective dehydration of the tissue specimens under investigation. This dehydration, for which ethanol most often is used, may influence the solubility of the slightly soluble calcium phosphates. To study the behavior of calcium phosphates in ethanol, stable neutral aqueous solutions containing the ions were mixed with ethanol in various ratios at 20 degrees C. After 24 hours, the precipitates formed wee identified by x-ray diffraction to be either apatite, brushite, or amorphous calcium phosphate. The results are discussed with reference to possible formation of calcium phosphate artifacts.