Chromogenic in situ hybridization

CISH, or chromogenic in situ hybridization, is a process in which a labeled complementary DNA or RNA strand is used to localize a specific DNA or RNA sequence in a tissue specimen. CISH methodology may be used to evaluate gene amplification, gene deletion, chromosome translocation, and chromosome number. CISH utilizes conventional peroxidase or alkaline phosphatase reactions visualized under a standard bright-field microscope, and is applicable to formalin-fixed, paraffin-embedded (FFPE) tissues, blood or bone marrow smears, metaphase chromosome spreads, and fixed cells.

http://www.invitrogen.com/site/us/en/home/Products-and-Services/Applications/Clinical-and-Diagnostic-Applications/Clinical-Pathology/CP-Misc/SPOT-Light-HER2-CISH-Kit/CISH-Technology-Overview.html