A FORMULA FOR THERMAL-STABILITY (T-M) PREDICTION OF PNA DNA DUPLEXES/

An empirical formula for thermal stability (T-m) prediction of PNA/DNA duplexes has been derived. The model is based on the T-m as calculate d for the corresponding DNA/DNA duplex employing a nearest neighbour a pproach, by including terms for the pyrimidine content and length of t he PNA to take into account the increased thermostability of PNA/DNA h ybrids and the asymmetry of the PNA-DNA heteroduplex. The predictive p ower of the T-m prediction formula was challenged with an independent data set not used for model building. The T-m of >90% of the sequences was predicted within 5 K; 98% of the predicted T(m)s differ by not mo re than 10 K from the experimentally determined T-m.