Temperature-dependent growth of smooth DNA film

We could form a smooth DNA film using synthesized short oligomers (10-mer adenine oligomer and thymine oligomer). The DNA film was observed by atomic force microscopy (AFM) in air. We found from AFM images that the DNA film growth strongly depended on sample preparation temperature within the range of 20 to 40 degrees C. The DNA film formed at 30 degrees C was markedly smoother than those prepared at other temperatures. This marked variation in morphology was attributed to the temperature-dependent interaction between oligomers. We discussed the interaction in light of the melting temperature of the DNA oligomers in saturated solution.