Fig. 3. Confocal laser microscopic images of E. coli cells (A) without and (B) with GCDs-220 (25.6 mg mL⁻¹) after incubation at 37 °C for 6 h: (a) bright field and fluorescence mode at excitation wavelengths of (b) 365, (c) 475, and (d) 532 nm.