Thin layer chromatographic screening test for amino acid anomalies in urine without desalting using internal standards

Effect of Slow Growth on Metabolism of Escherichia coli , as Revealed by Global Metabolite Pool (“Metabolome”) Analysis

“…In Fig. 1, with TLC plates developed with system A optimized for amino acid separation (22), the resolved and unresolved spots represent all water-soluble carbon-containing compounds of the cell in the 2-D space analyzed. System A resolved not only amino acids but also sugars like glucose and trehalose, as well as metabolites like UDP-sugars.…”

“…Some elutions required two consecutive developments with the same solvent system to achieve a good separation; in these elutions, the plate was dried for 20 min in a ventilated fume hood and then for 3 min at 80°C between different solvent runs. All of the four solvent combinations used were those described by other workers (18,21,22,27,42): elution of the first dimension twice with pyridine-dioxan-28% (wt/wt) ammonia-water (35:35:15:15, vol/vol) before elution of the second dimension twice with butanol-acetoneacetic acid-water (35:35:7:23, vol/vol) (system A); B-elution twice with propanolmethanol-28% (wt/wt) ammonia-water (60:20:20:20, vol/vol) in the first dimension, followed by elution twice with butanol-acetone-acetic acid-water (35:35:7: 23, vol/vol) in the second dimension (system B); development of the first dimension once with butanol-acetone-0.1 M phosphate buffer, pH 5 (40:50:10, vol/vol), and then elution of the second dimension once with butanol-2-propanol-0.5% (wt/vol) boric acid (30:50:20, vol/vol) (system C); and elution of the first dimension twice with chloroform-methanol-28% (wt/wt) ammonia (40:40: 20, vol/vol) and then once with butanol-acetic acid-pyridine-37% (wt/wt) formaldehyde (30:30:20:10) (system D).…”