This chapter describes a straightforward protein purification strategy for the specific separation of insoluble recombinant proteins (so-called “inclusion bodies”) located in the E. coli cytoplasm and their subsequent recovery in form of soluble recombinant proteins. Optimization of this technique can overcome in some cases the application of tedious and yield-reducing standard protein purification procedures. Due to the different behavior of individual recombinant proteins during separation, solubilization, and purification, subsequent purification steps may be required to obtain recombinant proteins in such a purity, that they can be used as antigen components of immunological test systems.