I've been using a lentiviral-based system with a pLenti expression vector in 293T cells and can purify the fragment, but yields are excruciatingly low (~300ug/L). There is quite a bit in the literature about using the pEE system with NSO cells to express antibodies, but will it really increase my yields that much (I've seen published yields of 60mg/L)? I need quite a bit of material for further in-vitro and in-vivo studies. Thanks for any and all help you can provide.