We have done an immunofluorescence experiment on rats' heart tissues (ventricle) using the Tyrosine Hydroxylase antibody. Now we have the results, there are signals running in the fibers. We want to quantify the signal using Image J, However, having difficulties in finding the right method that could be standardized, since the signals are widely dispersed in the tissues in all the sections. What area should be selected? What method should be used using Image J? Thanks for reading.