The PCR products amplified from the internal organs, muscles and brains of mice treated with SPZ once a day for five or ten days (groups G2, G3, G4 and G5), run on a 2.0% agarose gel. Line M is the molecular weight marker (DL 2 000 DNA marker). PCR products amplified from the heart, liver, lung, kidney, muscle and brain were loaded in lanes 1, 2, 3, 4, 5 and 6, respectively.