FAQ: Does plasmid size affect transformation efficiency (C2992)?

Yes. We transformed a series of plasmids ranging in size from 2.7 kb (pUC19) to 24 kb into NEB 5-alpha F´Iq competent E.coli (NEB #C2992H) and NEB 10-beta competent E.coli (NEB #C3019H) side by side. We noted that the transformation efficiency was affected by the plasmid size. NEB 10-beta chemically competent cells are more efficiently transformed with large plasmids than NEB 5-alpha F´Iq cells.