Patent ID: 8197758
Filing Date: 2012-06-12
Classification: C07F,G01N,Y10T

Abstract:
1. An optical labeling molecule for labeling a target analyte comprising: (a) a zwitterionic dye moiety comprising at least one positive or at least one negative charge moiety added to obtain a net neutral charge, wherein the positive charge moiety is selected from a group consisting of a quaternary ammonium group and a guanidinium group, and the negative charge moiety is selected from the group consisting of a sulfonate group and a sulfate group, and neither the positive charge moiety nor the negative charge moiety is titratable between the pH of 3 to 12; (b) a functional linker moiety; and (c) a titratable group moiety, wherein the titratable group is a tertiary amine which closely approximates the pK of the group removed from the protein by reaction with a functional linker.