dim standards this is especially suitable when more than one analytes are detected in some embodiments the internal standard comprises a plurality of bright standards and plurality of dim standards in one aspect the present invention provides a method of measuring one or more analytes in a sample the method comprises adding an internal standard to the sample the internal standard comprising a first standard and a second standard then the sample is loaded into a microfluidic device the internal standard and the analyte are separated by electrophoresis this is followed by the immobilizing the internal standard and the analyte a first image comprising the image of the first standard and the second standard is captured followed by the detection the analyte with an antibody to produce a second image a third image comprising the image of the first standard is captured finally the analyte is measured by comparing the first image the second image and the third image fig2 depicts one embodiment of an assay according to the present invention in which a standard is first added to a sample to be analyzed the sample contains proteins of interest the standard comprises a registration standard the bright standard and an additional standard the dim standard both are labeled with a label moiety comprising a fluorescent dye.