Method for labeling concentration density differentials of an analyte in a biological sample

A method for labeling concentration density differentials of a first analyte in a biological sample, the biological sample comprising a plurality of first analytes, the method including the steps of:

• a. binding a first target antibody linked to a first enzyme to the first analyte contained in a sample, the first enzyme capable of acting on at least two chromogens while bound to the first analyte;
• b. incubating the sample with a first chromogen for a first time period to generate a first color chromogen-enzyme product after the first enzyme reacts with the first chromogen while the first target antibody is bound to the first analyte, the first color chromogen-enzyme product reflecting light observable as a first color;
• and
• c. incubating the sample with a second chromogen while the first color chromogen-enzyme product is still present and the first enzyme has not been de-natured to generate a second color chromogen-enzyme product while the first target antibody is bound to the first analyte, the second color chromogen-enzyme product reflecting light observable as second color, and
• d. wherein a combination of the light observable as the first color and the light observable as the second color is observable as a third color while the first target antibody linked to the first enzyme is bound to the first analyte and the first enzyme has reacted with both the first color chromogen and the second color chromogen, and
• e. wherein the presences or absence of each of the first color, the second color, and the third color is useful to determine analyte density in the biological sample.