TAM identification: ISCytsp1
100 ng of the TAM library plasmid and 200 ng of plasmids expressing TnpB/reRNA were electroporated into E. coli (Bio-Rad, Gene Pulser Xcell) in 0.1 cm cuvettes under the following conditions: 1.8 kV, 25 F and 200 ohm. Approximately 50,000 colonies were collected in each experiment to ensure sufficient coverage of all possible 5 base combinations. Plasmids were extracted using a Plasmid mini Kit I (Omega). Approximately 200 bp amplicons surrounding the target loci were amplified with Accuprime Taq polymerase (Invitrogen) and a two-round PCR strategy to add Illumina adaptors and unique barcodes for each sample.