CISH Overview
 | 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. What CISH offers:
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About the Technology
 Invitrogen's CISH probes are created with Subtraction Probe Technology (SPT™), a proprietary technology that produces highly specific probes by significantly reducing the repetitive sequences found in human DNA. Consequently, our probes do not require the repetitive sequence blocking that is common for traditional cytogenetic DNA probes. |
  On Day 1, major steps include tissue preparation, heat pretreatment, pepsin digestion, probe addition, and denaturation/hybridization. Following an overnight hybridization step, Day 2 begins with a stringent wash before proceeding with the immunodetection steps. After using a standard tissue mounting procedure, the specimens are ready for interpretation on a bright-field microscope. |
CISH detection of non-amplified HER2 gene status (A) and amplified HER2 gene status (B) in different breast cancer tissue samples at 40X magnification.
How does CISH compare to IHC and FISH?
| CISH | FISH | IHC | |
|---|---|---|---|
| Signal stability | Archivable | Fades over time | Archivable |
| Microscope | Bright-field | Fluorescence | Bright-field |
| Magnification | 40x | 60–100x | 20–40x |
| CProtocol length | Overnight + 3 hr, 55 min | Overnight + 3 hr, 12 min | 3 hr, 2 min |
| Morphology | Good | Limited | Good |
| Amount of training required | Medium | High | Low |
| Internal control | Yes | Yes | No |
| Interpretation | Objective/quantitative | Objective/quantitative | Subjective/qualitative |
| Overall cost | Medium | High | Low |
Scientific Posters on CISH
- Impact of chromosome 17 polysomy on HER-2 testing results assessed by chromogenic in situ hybridization (CISH) - USCAP2008
- Performance of chromogenic in situ hybridization (CISH) in HER-2 immunohistochemistry-equivocal cases - USCAP2008
- Chromogenic in situ hybridization (CISH) is a reliable method for detecting HER-2 gene status in breast cancer - USCAP2008
- Chromogenic in situ hybridization (CISH): A practical method to confirm the immunohistochemical (IHC) results for HER-2 amplification in archival breast carcinoma samples
- Detection of ABL Gene Translocation and 5’- Deletion by Chromogenic In Situ Hybridization (CISH™)
- Screening C-Myc Translocations in archival lymphomas by chromogenic in situ hybridization (CISH™) with SPT™ C-Myc probe
- Detection Of EGFR Gene Amplification And Protein Expression By Chromogenic In Situ Hybridization (CISH™) And Immunohistochemistry (IHC) In A Series Of Archival Human Cancers
- EGFR and HER2 Gene Amplification and Polysomy In Non-Small-Cell Lung Carcinoma (NSCLC)
- Detection of topoisomerase IIa (TopoIIa) gene amplification and deletion by chromogenic in situ hybridization (CISH™) in archival breast carcinoma
HER2 CISH Tutorial
Take our tutorial to learn all about the HER2 CISH assay for educational purposes, or to certify your lab
CISH Products
