Expression of soluble recombinant proteins is the first aim of functional and structural studies. Biotechnology and pharmaceutical applications often require soluble proteins at high concentrations. We have found that normalised temperature factors (B factors), can be used to accurately predict the solubility of recombinant proteins expressed in Escherichia coli. Based on this finding, we developed SoDoPE (Soluble Domain for Protein Expression). The tool first identifies functional protein domains and predicts their solubility using normalised B factors. Options will be given to users to maximise the solubility of a target protein region, i.e., extended regions with higher probabilities of solubility. After finalising the target protein region, protein expression level can then be optimised at the nucleotide sequence level using our recently developed tool TIsigner.