There is a new generation of medicines under development that are based on natural molecules such as proteins or DNA. These will potentially be safer and more effective than current medicines but they are much more difficult to manufacture. Generally proteins are made in cells by biotechnology methods that are similar to those used in the fermentation of beer and wine. However, separation of the pure protein from the rest of the cell is much more challenging than the harvesting of ethanol. In this project we will investigate a new separation process based on coating proteins on the surface of crystals. This technique is known to work well with pure proteins but here we will investigate if it can be applied to the complex mixtures produced when processing cells. The aim will be to find specific conditions where the target protein can be purified from the other proteins and other cell components. If successful the research could potentially help speed up the development and reduce the cost of protein based medicines.