🧬 Molecular Biology & Oligonucleotide Analysis
DNA GC Content & Melting Temperature ($T_m$) Calculator
Analyze DNA/RNA primer sequences, calculate GC percentage, determine PCR annealing melting temperature ($T_m$), single-strand molecular weight, and generate reverse complements.
🧪 M13 Forward Primer (17 bp)
🧪 M13 Reverse Primer (17 bp)
🔬 T7 Promoter (20 bp)
✂️ EcoRI Site (GAATTC)
DNA Oligo Sequence (5' ➔ 3')
Whitespace and numbers are automatically ignored.
Melting Temperature (Tm)
54.0 °C (Wallace)
Sequence Length
17 bp
Molecular Weight
5,263 Da
Marmur-Doty $T_m$
50.5 °C
A: 6 (35.3%) | T: 1 (5.9%) | G: 5 (29.4%) | C: 5 (29.4%)
Reverse Complement (5'➔3'): ACTGGCCGTCGTTTTAC
DNA Melting Temperature Formulas
$T_m$ is the temperature at which 50% of the oligonucleotide duplex is denatured:
- Wallace Rule ($L \le 20\text{ bp}$): $$T_m = 2(A + T) + 4(G + C) \text{ }^\circ\text{C}$$
- Marmur-Doty Formula ($L > 20\text{ bp}$): $$T_m = 64.9 + 41 \times \frac{(G + C) - 16.4}{L} \text{ }^\circ\text{C}$$
- Recommended PCR Annealing Temperature ($T_a$): Typically set $T_a = T_m - 5^\circ\text{C}$.