Flow chart summarizing sponge and macrofoam swab sample processing and E. herbicola DNA extraction and purification procedures. Abbreviations: PB, 0.01 M PB; TBS, Tris-buffered saline with 0.1% Tween 20; HA, mixed cellulose esters; PBT, 0.01 M PB with 0.05% Tween 20; BSA, bovine serum albumin; TE, Tris-EDTA buffer.