<p>(A) Strategy for construction of DNA samples. DNA samples were constructed by two PCRs. The first PCR was performed to add universal sequence, a randomized T7 promoter, and a barcode sequence to the template. A second PCR was performed to amplify the DNA samples over 30 cycles. (B) Theoretical distribution of the number of base substitution for each randomization ratio. Blue line shows the retention rate at 90%. Orange line shows the retention rate at 70%. Black line shows the retention rate at 50%.</p
