FIG. 3.

Sensitivity of PCR-based assay for P. piscicida. Shown are amplicons of 10-fold serial dilutions of P. piscicida DNA starting from 1 ng without background DNA (A), with 1 μg of Rhdomonas sp. DNA (B), with 1 μg of K. micrum DNA (C), and with 1 μg of COMB4872 DNA (D). The arrows indicate the limit of detection (10 fg of DNA). Although light bands can be observed at higher dilutions, the arrows indicate those that are clear under UV light with the naked eye. Fifteen microliters of a 20-μl PCR mixture was applied for electrophoresis. (−), negative control with sterile water.