Background on Melting Temperature (Tm)
Melting temperature is the temperature at which a DNA double helix dissociates into single strands. In case you want to learn more about it. Please see the videos below:
Calculate DNA Melting Temperature
$ conda install -c conda-forge biopython
Next, Biopython provides three methods to compute the melting temperature as described below by their definitions:
- Tm_Wallace: ‘Rule of thumb’
- Tm_GC: Empirical formulas based on GC content. Salt and mismatch corrections can be included.
- Tm_NN: Calculation based on nearest-neighbor thermodynamics. Several tables for DNA/DNA, DNA/RNA, and RNA/RNA hybridizations are included. Correction for mismatches, dangling ends, salt concentration, and other additives are available.
Now, there are three examples on how all the methods differ from each other
>>> from Bio.SeqUtils import MeltingTemp >>> sequence = "TAGTGATGACTGTCGTAGCTGTCGTAGATGTGTCATAAAAAA" # Rule of thumb melting temperature >>> MeltingTemp.Tm_Wallace(sequence) >>> 116.0 # GC melting temperature >>> MeltingTemp.Tm_GC(sequence) >>> 60.98 # nearest-neighbor melting temperature >>> MeltingTemp.Tm_NN(sequence) >>> 62.86
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