During this study, we have occasionally come across novel and previously unreported observations regarding enzymatic mechanisms. This includes a possible pH-or a buffer composition-based inhibitory mechanism of Exo III and an Mg 2+ -dependent modulation of enzymatic activity probably for both Exo I and III. We have tried our best to explain these observations without significantly deviating from the main objective of this work. These observations would be taken up in more detail in future experimental investigations. Altogether, this work may serve as a possible template for robust preparation of cDNA from unmodified oligonucleotides, would help design RCA-based molecular diagnosis and bioanalytical assays without non-specific amplification, and is expected to trigger new mechanistic investigations into enzymatic activity.