Please help me!! I am trying to cloning a 8kb Drosophila genomic DNA fragement from lamda phage into a 10kb plasmid. My plasmid got deleted during cloning. It becomes much smaller than 10kb, and about a half of them with the same size on agarose gel. I had used different host strains, DH5alpha and Stratagene SURE cells but the same problem happened no matter which strain I used. Does anybody have the same/similar problem as I have? I am appreciate for any suggestions in advance.