Figure 4.
Serial transfer experiments with T7 DNA in cell extract. In every generation the phage DNA was incubated for 4 h at 29 °C in freshly supplied cell extract, followed by a dilution to 3 % (v/v) of its original amount. The DNA concentration of each sample was measured by qPCR at the beginning of the incubation and after 4 h of incubation. Insets: concentration of active T7 phages determined using a plaque assay. All data points represent technical triplicates. In (A) incubation was carried out in bulk solution, while in (B) cell extract and phage DNA were incubated in picoliter-sized water-in-oil droplets. After four dilution steps the theoretical amplification is 80-fold in (A) and 15,698-fold in (B). The given uncertainties are S.E.