This is a simple formula used to calculate the temperature ＞＞ Tm = 2(A+T) + 4(G+C) ℃

I curious about the Nearest-neighbor method .

I get the deltaH and deltaS but when I put this 2 parameter in the formula I got a very small numer than the correct answer .

Can someone teach me how to count ?

wiki: https://en.wikipedia.org/wiki/Nucleic_acid_thermodynamics

this is my primer : GCTAGTTCAACGTCAAGTGTG

Enthalpy : -167 cal/mol

Entropy : -455.9 cal/mol-K

I use this fumula

Tm = delta H / (delta S + 1.99 x ( ln(c/4)) - 273.15 = 87.14 C

Tm = (-167 ) / ( -455.9 + 1.99 x ln(c/4)) - 273.15 = －272.8

87.14(correct)

-272.15(my answer)

where c is probe concentration. In this case 0.1

Can someone teach me how to count ? thx!