FIG 1.

Quantification of total and viable cells (in DNA copies/mL) using oil-enveloped bacteria, a metal bath, and a DNA kit on day 40 during viable but nonculturable (VBNC)-state development of Vibrio cholerae strain C6706. (A) Total cells were measured without PMA treatment (PMA⁻), and viable cells were measured after PMA treatment (PMA⁺). qPCR, quantitative PCR; ddPCR, droplet digital PCR. Error bars represent the mean and standard error of measurement. (B) The samples were treated with PMA, and the oil-enveloped bacteria method was used to obtain ddPCR results without PBS washing and with PBS washing one and three times.