Could someone please explain how MCS are included into the lacZ gene? Or are they naturally occurring? We all understand the concept of blue-white screening where a disrupted lacZ gives only white colonies whilst intact lacZ give blue ones.
What about the MCS? Wouldn't it affect the lacZ in some way that the reading frame is altered since the insertion of different RE sites?
I tried to reason with myself that these RE sites are naturally occurring but I happen to see a few examples of pGEM plasmids (pGEM-7Zf, -11Zf and -13Zf) having different MCS in the lacZ gene.
Reason I ask is that I wanted to include a few RE into an existing gene but not wanting it to lose its function.
Edited by dreamchaser_jc, 26 April 2010 - 09:26 PM.