Application label and method

The first two design steps in the immunocytochemistry experiments are (1) whether to use fluorescence or enzyme-based labels and (2) which application method is 

Immunocytochemistry, DOI 10.1007/978-l-4419-1304-3 9, Springer Science+Business Media, LLC 2010 

Detection resolution measures the degree to which the label localizes to the P antibody site in the cell. The highest detection resolution occurs when the label is bound directly to the 1° antibody. Direct immunocytochemistry with fluorescent label uses no antibodies or molecules to bridge the label to the D antibody. Graphically, the highest detection resolution occurs with the label attached directly to the 1° antibody (Fig. 9.1a, arrow). 

Low resolution occurs when enzymes (i.e., HRP), localized in the microscope generate a reaction product that spreads from the site of the enzyme and decreases the detection resolution. An example of lowest detection resolution would be ABC immunocytochemistry, because an enzyme is the label and it is bridged to the primary antibody by avidin-biotin (Fig. 9.1a, number 2, Low resolution). Any additional molecules that bind to the 1° antibody and bridge the label away from the 1° antibody will decrease the detection resolution. In planning experiments, resolution is important when antigens are localized to a discrete location. 

Detection sensitivity measures the intensity of label in the microscope following the immunocytochemical procedure. Detection sensitivity is a direct measure of the amount of label at the 1° antibody location or the amount of label generated in the case of an enzyme. An example of high detection sensitivity is ABC immunocytochemistry, where a large amount of HRP reaction product is generated by a single 

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