The conditions for producing linear arrays of magnetoferritin on quartz surface are described. Two-dimensional ordered array of mFT on a quartz surface can be formed by spreading a concentrated solution of mFT on quartz and evaporating the film at 90% relative humidity and at room temperature. Under these conditions, mFT forms a close packed linear arrays with hexagonal symmetry. Drying at 50% relative humidity and at room temperature produced structures containing both hexagonal and orthogonal symmetries. A surface loading of 5-10 mu g/cm(2) was found to be ideal for forming a paracrystalline structure with a large crystal size.