Figure 3. Endotoxin concentration (EU·ml⁻¹) of phage preparations as measured by the Pierce™ LAL Chromogenic Endotoxin Quantitation Kit.

Raw lysates had starting endotoxin concentration of 4.7 × 10⁴ EU·ml⁻¹. The PoT protocol and traditional method reduced endotoxin concentrations to 8.3 × 10³ and 3.2 × 10⁴ EU·ml⁻¹, respectively. Filter-sterilized SM buffer (0.2 EU·ml⁻¹) is shown as a negative control, dotted line represent the desired 20 EU·ml⁻¹ cut off. Endotoxin concentration data shown are averages of triplicates from a single experiment.