Analytical repeatability, reproducibility, and linearity
Within-run precision (repeatability) and within-laboratory precision (reproducibility) were measured using different concentrations of sheared A. baumannii and K. pneumonia DNA samples. The within-run coefficients of variations (CVs) of A. baumannii andK. pneumonia were 2.7%–5.3% and 2.3%–9.5%, respectively. The within-laboratory CVs of A. baumannii and K. pneumoniawere 5.3%–7.5% and 7.4%–9.7%, respectively (Tables 5 and 6).
Linearity was determined by a 2-fold serial dilution of the DNA template. Figure 1 shows the regression lines that represent the linear relationships between DNA copy numbers and concentrations of A. baumannii (R 2 = 0.9925) and K. pneumonia (R 2 = 0.9915), respectively. Taken together, these results indicate that ddPCR has excellent repeatability, reproducibility, and linearity in detecting A. baumannii andK. pneumonia in blood samples.