Figure 7.
Simplified schematic of the optimized fast filtration sampling, quenching, extraction, and sample purification protocol for accurate, high-precision metabolic profiling of E. coli. Critical considerations (bold), parameters (italic), and recommended values, materials, and procedures discussed throughout this study are summarized in the lower panel. PVDF, polyvinylidene fluoride; ACN, acetonitrile; LN2, liquid nitrogen; ISTD, internal standard; MS, mass spectrometry; S/N, signal to noise.