FIG 2.

Hydrogen peroxide (H₂O₂) generation from agar with increasing phosphate concentrations after autoclaving agar and phosphate either together or separately. Two preparation methods are represented: 0.75 g of Bacto agar was suspended in 50 ml of buffer with phosphate concentrations ranging from 0 (i.e., pure H₂O) to 30 mM (Na₂HPO₄-KH₂PO₄, pH 7.0), and agar and phosphate were autoclaved together; alternatively, 0.75 g of agar was suspended in 50 ml of water and autoclaved, and then autoclaved phosphate buffer (100 mM Na₂HPO₄-KH₂PO₄ stock, pH 7.0) was added to final concentrations ranging from 1 to 30 mM. Means of at least five independent experiments with standard deviations are shown.