electroporation with DH5a vs XL10-Gold - any difference for large plasmids? (Aug/02/2011 )

I am trying to generate a mutant library for a 7.4kb plasmid from ligation. I've been working with DH5a and recently got hold of some XL10-Gold, which supposedly gives better transformation efficiency for large plasmids and ligation products.

1) XL10-Gold is sold as a chemical competent cell for large plasmids and ligation products. Can I prepare electrocompetent cells from the stock? Would it perform as well as the chemical competent ones? Just curious why it's not sold in the electrocompetent form as well.

2) If I prepare electrocompetent DH5a and XL10-Gold with the same transformation efficiency using pUC18, would XL10 transform better for larger plasmids?

Thanks!

You can certainly prepare electrocompetent cells from that stock. In general the transformation efficiency for electroporation is higher than most chemical transformation. I don't know how that would work for large constructs (but I don't think of 7.5Kb as especially large).