Hydroxyapatite, Ca5(PO4)3(OH)2, is a form of calcium phosphate that is widely used in preparative biochemistry for the separation or purification of monoclonal and polyclonal antibodies and other proteins, nucleic acids, viruses, and other macromolecules. It is useful for preparative work in column or batch modes, and for quantitative analysis of proteins or nucleic acids. Its advantages include:
- Unique selectivity — separation on hydroxyapatite is not primarily dependent on molecular weight, charge density, or isoelectric point. This makes hydroxyapatite chromatography a valuable complement to other separation techniques
- High capacity — surface area of about 50 m2/g
- Specificity — nonspecific adsorption of hydrophobic substances is minimized by the inorganic crystalline matrix of hydroxyapatite. Hydroxyapatite displays negligible adsorptive capacity for low molecular weight substances such as mononucleotides, salts, and amino acids
- Chemical and thermal stability — wide range of chemical compatibilities (aqueous and inorganic solvents), thermal stability (autoclavable), and pH tolerance (pH >5.5) permit the use of hydroxyapatite under conditions that optimize the binding of nucleic acids and proteins
Bio-Gel HT hydroxyapatite is ideal for the purification of proteins, nucleic acids, and other macromolecules. Bio-Gel HT is shipped suspended in 10 mM sodium phosphate buffer containing 0.02% NaN3. This material gives excellent resolution at a high flow rate because of its large particle size. Bio-Gel HT hydroxyapatite can be sanitized in NaOH.