information on quantitation of fluroscenece channels in TIFF file using Image J

[Joseph, Ajith M]

I have fluroscence images of 20x magnification of tissue sections. These
sections have imaged under FITC, Cy3, Cy5 and DAPi channels. I would
like to quantitate the cells expressing markers in each of the channels
using Image J. Kindly advise
NB I am new to using Image J
Thanks for the suggesstions and advice
Ajith