Ceramic hydroxyapatite beads for high performance liquid chromatography (HPLC) was already reported to be a cation exchanger in type and proteins were adsorped and eluted with changing the concentration of sodium phosphate buffer solution. Hydroxyapatite crystalline impregnated paper (HAP paper) which was made of micro crystalline and paper fiber, but without sintering process was used for filtration or separation of biological macromolecule materials. A circular sheet of HAP paper was cut into a suitable size and (0.76mm I. D.) and placed in a column for HPLC of protein. Chromatography was performed across the HAP paper sheet. One sheet of HAP paper could adsorbed about 12μg cytochrome c. A pile of these sheets could also be used for the chromatography of protein as well as hydroxyapatite beads column. HAP paper was useful not only for the separation of protein but also for the preliminary sample clean up for the HPLC, electrophoresis or various immunochemical treatment
