Help please!!! - Delection after cloning (May/30/2002 )

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.

Thanks,

Mary

hi,
Why don't  you use another plasmid to replace your
10kb plasmid??
Maybe the plasmid is contaminated.