A cloned DNA sequence was used to probe a Southern blot. There were 2 DNA samples on the blot, one from white blood cells and the other from a liver biopsy of the same individual. Both samples had been digested with HpaII. The probe bound to a single 2.2 kb band in the white blood cell DNA, but bound to 2 bands (1.5 and 0.7 kb) in the liver DNA.
a ) What are possible explanations for this difference?
b ) How would it affect your answer if you knew that white blood cell and liver DNA from this individualboth showed the 2 band pattern when digested with MspI ?