BL21 is RecA+, whereas DH5alpha is RecA- and thus more appropriate for
cloning purposes. BL21 also produces lower levels of proteases and thus
better for expression of recombinant proteins.
"fisher" <foolio_j88 at yahoo.com> wrote in message
news:%KW5a.1377$XR3.40892 at news.itd.umich.edu...
> What's the difference between these two??