It is possible that the protein forms aggregates, or that the temperature is too low. Precipitation can be reduced by running the purification at room temperature, performing batch mode binding to reduce high local protein concentration, and/or adding solubilization reagents to working buffers (i.e. 0.1% Triton X-100 or Tween20, < 10 mM β-Mercaptoethanol, up to 2M NaCl or cofactors such as Mg²⁺).