I would like to know why do we use a donor vector when we clone a desired gene to introduce it into a destination vector for expression analysis? why we don’t go directly to introduce our gene into the destination vector without recombining it into the donor vector?
I guess, you are talking about some system like GATEWAy, right?
Well, in this system, you use only one cloning, that into the entry vector and from these you can recombine it into many other vectors, you can do overexpression, fusion at N- or C-end with any peptide etc. etc. 😉