Hello everyone,
I am having a trouble in keeping my plasmid inside the bacteria. My plasmid is a Lentiviral plasmid of 7 kb and with the insert that I cloned is now 9 kb. The resistance gene is against Ampicillin. After cloning I transformed the ligation product into Stbl3 bacteria and had low yield of plasmid (15 ng/uL), then I tried DH10B and after first passage it was nice (240ng/uL) but then when I do glycerol stock for -80 degree, the yield was very low again (5ng/uL). Then I tried NEB Stable and the first passage was nice again (430ng/uL) but after -80 stock, I am getting again low yield (10ng/uL)...
So I don't know what to do, to have high yield of plasmid every passage..
If anybody has faced with this problem can share the knowledge it would be very nice.
Thanks!!