Why is the Tm provided on your oligonucleotide specification sheets different from the calculated Tm I obtained when I designed my oligos?
Oligonucleotides designed using our online SciTools™ Web Tools
are ordered for a wide variety of applications, and not solely for PCR. The Tm
shown on the spec sheets is calculated based on default conditions of 50 mM Na+
without taking into consideration Mg2+
and dNTP concentrations, both which influence Tm
. To determine the correct Tm
or your oligo under your specific reaction conditions, enter the sequence into the online OligoAnalyzer Tool
, making sure to change the defaults to your reactions conditions.