Using the fabricated condensates, we carried out melting experiments to determine their dissolving temperature 𝑇 " , above which the condensates could be observed to become dispersed with an incremental temperature increase. In good agreement with the calculated 𝑇 ! , a series of the melting experiments yielded a higher 𝑇 " in the RNA condensates of rSE-ended X-motifs than the DNA analog by 20°C. We also observed a decrease of 𝑇 " in the order of KL_Ori > KL_Mu1 > KL_Mut2. In the middle temperature range, we obtained liquid-like states in the SE-assembled condensates at >60°C for dSE and >80°C for rSE. The droplet-like shape of dSE-assembled DNA condensates was reminiscent of thermally annealed DNA droplets fabricated using the same motif design. The rSE-assembled RNA condensates showed marked wetting on the glass plate, indicating a liquid state. In other motifs, no distinct droplet-like objects were observed. For example, the KL_Mut2-assembled RNA condensates underwent no significant rounding-up until complete dispersion beyond 50°C. Finally, these melting experiments suggested KL_Mut2 as an appropriate KL for designing the sensing X-motif RNA that can operate at moderate temperatures.