PCR additives Betaine, DMSO and formamide reduces the Tm and the complex secondary structure thus the duplex stability. Tetramethyl ammonium chloride (TMAC) increases the specificity of hybridization and increases the Tm. The use of TMAC is recommended in PCR conditions using degenerate primers.
These PCR additives and enhancing agents have been used to increase the yield, specificity and
consistency of PCR reactions. These additives may have beneficial effects on some amplification and
it is impossible to predict which agents will be useful in a particular context and therefore they must be empirically tested for each combination of template and primers.
TMAC is used to reduce potential DNARNA
mismatch and improve the
stringency of hybridization reactions. It
increases Tm and minimizes mis-pairing. TMAC is generally used at a final
concentration of 15-100mM to eliminate nonspecific