At 0.2 M Na1, the melting temperature of double-stranded DNA is given by the formula, Tm 5 69.3 1 0.41 (% G 1 C). The DNAs from mice and rats have (G 1 C) contents of 44% and 40%, respectively. Calculate the Tms for these DNAs in 0.2 M NaCl. If samples of these DNAs were inadvertently mixed, how might they be separated from one another?.