I was working on a Human protein and expression and solubility is good in E.coli and purification is One step (His-Tag), and i need to cleave the Histag before screens, if not the protein will precipitated and Aggregated, but after trying for 1.2 years i have crystals and they are with Organic solvents, (10 conditions), these crystals are inter grown like broccoli shaped and i tried seeding, but it is not successful, and even i tried with additive screen but the result is the same .... is there is any idea to increase the size and shape of my protein crystals.