Fig. 5. Detection threshold evaluations. Average differences (±SEM) from R, for each protein concentration; pH = 6.8, (panel A); pH 5.1, (panel B).* = protein concentration
significantly different from R (p 6 0.05) ** = protein concentration significantly different from R (p 6 0.01) *** = protein concentration significantly different from R
(p 6 0.001).