Fig 2.
Cycle threshold values related to initial copy numbers of cloned korB genes from six plasmids (pB10, pEST4011, pKJK5, pMCBF1, pQKH54, and RP4) representing the different IncP-1 subgroups and pKS208. Solutions of korB fragments ligated into pGEM-T (Promega) with similar concentrations (optical density at 260 nm [OD260], 0.5; OD260/OD280 ratio, >1.8) were serially diluted and applied to the developed real-time PCR 5′ nuclease assay. The gray area and dashed lines indicate 95% confidence limits and prediction limits of linear regression analysis, respectively.