Levels of berberine in single dormant and germinated spores.

Spores were incubated for 60 min at 37°C in buffer and different concentrations of berberine without (dormant spores) or with (germinated spores) 10 mM L-valine, and Raman spectra were measured by LTRS. Spores were also incubated similarly in buffer and valine plus 20 μg/mL INF55 before Raman measurements. Berberine levels in spores were calculated as described in Methods. The curves shown are averages of data from ~ 30 individual spores.