I am having a gene synthesized (~1300bp) that was originally expressed in E.coli but I want to use it in a mammalian expression vector. I designed the gene and had it optimized by GeneArt from Invitrogen and also got a quote from DNA2.0. The price is more than double from DNA2.0, so I was wondering if anyone had experience with codon optimization for mammalian genes with either of these vendors. Particularly, is the extra cost worth it from DNA2.0?