Enter your oligo sequence in the box and press "Calculate"
Melting Temperature (Tm)  °C 
%GC content
Molecular Weight:  daltons (g/M) 
OD of 1 is equal to  pmol/ml (nM). 

[Original Javascript program by Eugen Buehler,
University of Pittsburgh School of Medicine]


The common Tm formulas for calculating the theoretical Tm of an oligo are:

The simlest formula:

Tm = 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)

Salt-Adjusted Tm Calculation Formula:

Tm= 81.5 + 16.6 x (log10{[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



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