Pre-treatment is an essential step for effective FISH on Formalin-Fixed Paraffin-Embedded (FFPE) tissue sections. This kit contains key reagents used to pretreat FFPE tissue sections from dewaxing with xylene through proteolytic digestion to helps permeabilization of cell membranes to facilitate penetration of fluorescence labeled probes. After proteolytic digestion, proceed the subsequent steps with the FISH assay protocol.