Figure 1.

HPLC trace of a fully reduced 5 µm PQH₂ standard (blue) and a fully reduced PQH₂-containing extract from Synechocystis sp. strain PCC 6803 (green). Samples were reduced with NaBH₄. The peak in the extract eluting at 8.5-min coelutes with the PQH₂ standard. Fluorescence excitation/emission was at 290/330 nm. The cutoff at 1,000 mV is the upper detection limit of the system. [See online article for color version of this figure.]