Working backwards from a construct? - (Aug/11/2014 )

So I have a construct created with my gene insert and vector. I tried to express it in DE3 cells but it wouldn't work, I think the issue is that the insert is too big.

Just wondering if there is a way to go back from my construct, take out the gene, shorten it and start again? I have to work backwards from the construct.

Thank you in advance!

What do you mean too big an insert? Size of insert is unlikely to be the problem, it is far more likely that there is either a problem with the plasmid itself (insert not in frame, promoter missing), or that the product is toxic, or that the cells aren't inducing properly.