text: The efficiency of duplex sequencing depends on the final number of DCSs which is directly related to the number of reads in each family (family size). If the family size is too small then the DCS can not be assembled and if too many reads are sharing the same tag, the data yield will be low. Family size is determined by the amount of DNA template needed for PCR amplification and the dedicated sequencing lane fraction. The optimal tag family size is between 6 and 12 members. To obtain the optimal family size, the amounts of DNA template and the dedicated sequencing lane fraction need to be adjusted. The following formula takes into account the most important variables that can affect depth of coverage (N=40DG÷R) where "N" is the number of reads, "D" is the desired depth of coverage, "G" is the size of DNA target in base pair, and "R" is final read length.