A balanced incomplete block design (BIBD) for three treatment groups (T1, T2, T3) with one subject per treatment group (T11, T21, T31) and two technical replicates of each (T111, T112, T211, T212, T311, T312). After fragmentation, each of the three samples is bar coded and divided in two (e.g., T11 would be split into T111 and T112) and then pooled and sequenced as illustrated (e.g., T111 is pooled with T212 as input to lane 1).