Coding Intrinsic Disorder into DNA Hybridization Probes Enables Discrimination of Single Nucleotide Variants over Wide and Tunable Temperature Ranges

DNA hybridization probes are commonly used tools to discriminate clinically important single nucleotide variants (SNVs) but often work at elevated temperatures with very narrow temperature intervals (Delta T). Herein, we investigated the thermodynamic basis of the narrow Delta T both in silico and experimentally. Our study revealed that the high entropy penalty of classic hybridization probe designs was the key attributor for the narrow Delta T. Guided by this finding, we further introduced an entropy-compensate probe (Sprobe) design by coding intrinsic disorder into a stem-loop hybridization probe. Sprobe expanded Delta T from less than 10 degrees C to over 30 degrees C. Moreover, both Delta T and the optimal reaction temperature can be fine-tuned by simply altering the length of the loop domain. Sprobe was clinically validated by analyzing EGFR L858R mutation in 36 pairs of clinical tumor tissue samples collected from lung cancer patients, which revealed 100 % clinical sensitivity and specificity. We anticipate that our study will serve as a general guide for designing thermal robust hybridization probes for clinical diagnostics. Classic hybridization probes for discriminating single nucleotide mutations typically work at elevated temperatures and in very narrow temperature intervals (Delta T) due to the high entropy penalty. By adding intrinsic disorder into hybridization probes, we successfully expanded Delta T from less than 10 degrees C to over 30 degrees C.+image