There is a well-described protocol for the incorporation of selenomethionine into the protein of interest by supplementing excess selenomethionine to the E.coli. However, incorporation of selenocysteine may not be that simple as selenomethionine as selenocysteine is a natural occurrence amino acid which has a specific tRNA for it. Does anyone has a protocol for the incorporation of selenocysteine into the protein of interest in E.coli expression system? Thank you in advance.