The invention claims a process for the recovery and/or purification of a protein comprising the sequence of Annexin A5 (AnxA5) from a composition that comprises the AnxA5 protein and a calcium metal ion chelator, characterised in that the process comprises subjecting the composition to an anion exchange resin in order to perform an anion exchange step and thereby recover and/or purify the AnxA5 protein from the composition, and further characterised in that the anion exchange step is conducted in the presence of additional selected metal ions, wherein the additional selected metal ions are selected such that the calcium metal ion chelator has a binding affinity for the selected metal ions that is greater than its binding affinity for the anion exchange resin, but less than its binding affinity for calcium ions. Compositions comprising the purified AnxA5 and its medical uses are claimed.
