High-flow-rate hydroxylapatites.

We have established a novel and simple method for preparing rigidly crystallized or granulated hydroxylapatites, which showed flow rates one order of magnitude higher in column chromatography than those of the Tiselius specimen (1). The essential difference in the procedures from the Tiselius method is that calcium phosphate, the precursor of hydroxylapatite, is generated not at room temperature but at either 45 or 95 degrees C. The capacities of the two hydroxylapatites for binding and fractionating protein, RNA, and DNA upon column chromatography were similar to those of Tiselius's hydroxylapatite. The 95 degrees C specimen can be dried with no change in the properties. Because of the reproducibly observed properties, including the extremely high flow rate with ease in handling as well as low cost and simple procedures with no additives and with no special equipment in preparation, our hydroxylapatites seem to be best so far for routine laboratory use.