DH5a vs XL1Blue

Alistair Forrest zzalforr at fox.uq.net.au
Fri Dec 8 17:44:19 EST 2000


I didn't know about the lacIq thing and the XL1 blues giving tighter 
repression, however in my experience i've found XL1-blue to give a higher 
success rate in maxi-preps when compared to DH5alphas.

Take the same plasmid, tansform into XL1-blues and DH5a and do a minprep
->DNA OK
take some of the miniculture and seed maxi
XL1-blue -> DNA most of the time
DH5alpha -> DNA less of the time (bugs spat out plasmid??)

The XL1 blue's are much slower growing, tighter control?

For larger plasmids I use STBL2's, My XL1-blues are much more competent, 
but the STBL's are basically "never fails" when it comes to maxi's. When 
the XL1 blues work for maxi's they generally give higher yields than the 
STBL2's, but the STBL2's work almost all the time and give a yield 
approximately 70% that of the XL1-blues.

cheers,
	Al






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