
The common Tm formulas for calculating the theoretical Tm of an oligo are: The simlest formula: T_{m }= 4°C x (number of G’s and C’s in the primer) + 2°C x (number of A’s and T’s in the primer) SaltAdjusted T_{m} Calculation Formula: T_{m}= 81.5 + 16.6 x (log_{10}{[Na^{+}] + [K^{+}]}) + 0.41 x (%G+C) – 675/n Where: n is the number of nucleotides of the oligo [Na^{+}] and [K^{+}] are the final concentrations of the sodium and potassium ions in the reaction, respectively 