DNA samples were mixed to create log-distributed abundance, which allows the user to easily assess the detection limit of a microbiomics workflow. 1 l of the standard (11 ng DNA) can be used to assess the detection limit of as low as the abundance ofStaphylococcus aureus contained in the standard, which is 0.000089% by relative abundance or is equivalent to the amount of DNA from 3 cells. If desired, the standard can also be used to mix with human genomic DNA, e.g. Human HCT116 DKO DNA (Cat. No. D5014-1), to mimic a human microbiome sample.