Cutting a DNA strip in half

No.12260747 ViewReplyOriginalReport
What is the probability to cut a DNA strip in half when for example slicing a piece of meat? I guess it happen all the time, but if so a DNA test may pick up half a DNA... Is there a probability analysis with X number of DNA parts and you have to collect Y in order to be sure you have found Z because it is assumed to be of higher concentration?

Just curious!