Analysis of monocyte phosphoproteome by ProQ staining. (A) Specificity of pro Q stain for phosphorylated proteins. Lane 1: Pro Q staining of monocyte lysates. Lane 2: Same cell lysates treated with protein phosphatase (80 units/ml) for 60 minutes at 30°C prior to SDS-PAGE/Pro Q staining. Lane 3: Sypro Ruby fluorescence staining of Lane 1. Lane 4: Sypro Ruby fluorescence staining of Lane 2. A protein band at about 25 kDa is consistent with Mr of protein phosphatase added to the sample. (B) A 2D gel of monocytes stained with Pro Q diamond phosphoprotein dye. Arrows point to the protein spots with IDs and positive for phosphorylation stain.