The production of recombinant protein involves the transfection of cells with the desired gene into a DNA vector. The gene is then converted into protein using the host cell’s machine. This expressed protein can then be extracted by lysing the cell and a subsequent purification step. 

Prokaryotic and eukaryotic expression systems are widely used. Every system has advantages and disadvantages. The specific expression system is chosen depending on economic and qualitative aspects such as the type of protein, function and desired protein yield. If you are looking for mammalian recombinant protein expression visit for the details.

Expression systems for bacteria, yeast, insects and mammals are widespread. Recently, researchers have also used a cell-free expression system.

Bacterial expression system

They offer large-scale production of recombinant protein in a short period of time (the E. coli doubling time is 20 minutes). Simple cultivation conditions (medium, additive) that can be measured and are inexpensive are required. The disadvantages of this system include difficulties in expressing certain mammalian proteins, accumulation of proteins such as inclusion bodies, contamination by protease proteins from host proteins resulting in degradation of expressed proteins, and accumulation of endotoxins.

Yeast expression system

A well-defined economical eukaryotic expression system. It combines the advantages of prokaryotic and eukaryotic expression systems. This system is used to express secretory and intracellular proteins. This system offers high protein yield, less expression time, post-translational modification, and requires a simple environment. This system can be optimized for high protein (gram) expression with the help of a fermenter.