How to calculate melting temperature of DNA “2+4 rule of thumb“

The melting temperature (Tm) is the temperature at which one-half of a particular DNA duplex will dissociate and become single strand DNA. The stability of a primer-template DNA duplex can be measured by its Tm. Primers with melting temperatures in the range of 52-58°C generally produce better results than primers with lower melting temperatures. While the annealing temperature can go as high as 72°C, primers with melting temperatures above 65°C have a higher potential for secondary annealing. Primer length and sequence are of critical importance in designing the parameters of a successful amplification. The melting temperature of a nucleic acid duplex increases both with its length, and with increasing GC content. A simple formula for calculation of the (Tm) is: Tm = 4(G C) 2(A T) °C The actual (Tm) is influenced by the concentration of Mg2 , K , and cosolvents. There are numerous computer programs to assist in primer design. The formula given above for (Tm) is simplistic; there are many primer design programs which use more complex nearest-neighbor thermodynamics values #singleStrandDNA #RnaSplicing #Alleles #Genotype #Primers #meltingTemperature #nucleicAcid #Prokaryotes #molecularBiology #genomes #Proteins #Isochromosome #GeneExpression #Chromosome #thermodynamics #Phenotype #ChromosomeArm #Genes #GeneStructure #DNA #gene #genome #GCContent #Iherb #GeneticsLecture #Genetics #Rrna #GeneticTesting #GeneticCode #eukaryotic #DNAMolecule #codon #sequence #primer #PCR #PolymeraseChainReaction #PCRPrimer #LabLife #Microbiology #labTips