
Good luck youll get there eventually!

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Thanks Enthusiast for your reply. I will try using the SOC medium instead of LB broth. However, the XL-1 blue supercompetent cells are running out. Hence, I have to substitute it with self-prepared supercompetent JM109, which we have tested its transformation efficiency using pUC18. The plates shows good competency, however, when trying it (supercompetent JM109) with my dpn1 digested pcr product, it turns out no colony. I wonder what could went wrong.
Anyone could help with this as I have been repeating the procedure for quite some time. Thanks lots!!