Lambda DNA, Methylated from Ecoli

[Smriti]

Hi All,

Recently I ordered Lambda DNA from Sigma which says "Methylated from Ecoli- partially cleaved by Bcl I, Cla I, Mbo I, Mbo II, taq I and Xba I". Similarly, the Non-methylated version is completely cleaved by these enzymes.

What type of partial or complete cleavage is this? Is this cleavage within Lambda DNA or some cleavage between Lambda and E coli DNA?

If this cleavage is within Lambda DNA, then how do we see a single band of 48Kb and not a smear of range of fragments.
Can anyone explain this?

Thanks