In transient expression, various parameters can be optimized to enhance protein yield, transfection efficiency, and overall expression performance. Key parameters include: 

Transient Expression: 

Cleavage sites are used to remove tags from recombinant proteins after purification to obtain the native protein. Here are some commonly used cleavage sites: 

Mammalian expression systems use various tags to facilitate purification, detection, and visualization of recombinant proteins. Here are some commonly used tags: 

Mammalian cell expression systems are widely used for producing recombinant proteins, especially those requiring complex post-translational modifications. Here are some commonly used mammalian cell types and their characteristics: