From what I understand, the gateway technology is a lab method to obtain cloning and expression vectors based on the property of phages to recombine its genetic material with bacterias. However, why do I need to perform the BP reaction, if I want to obtain an expression clone of a certain gene? Why can’t I use an attL-PCR product or a linearized attL DNA and make a reaction with the destination vector, therefore obtaining the expression clone attB in the end? I can’t understand why we have to perform the first reaction! Help!
The point is that you get your gene into an universal vector from which you can easily transfer it into variety of destination vectors without any need of further PCR as PCR is often troublesome and introduces mutations.