TABLE 2.

iTRAQ Labeling Scheme for the Comparison of Four Labeling Reaction Compositions

Label	Volume to take of digest to make 5 μg protein (μL)	Dilution with dissolution buffer (μL)	Ethanol to add to label (μL)	Label volume to add after adding ethanol (μL)	Water to add to quench labeling reaction (μL)
115	1.75	38.25	70	All	100
116	1.75	0	70	All	100
117	1.75	0	70	5.08	100

Protein digest (5 μg) was used in each label reaction. Label 114 was taken from experiment in Table 1 as 12.3 μL and was combined to all the other labels at the end.