Fluorescent in situ hybridization (FISH)

Fluorescent in situ hybridization is an important method for genetic mapping and gene expression profiling. This technique exploits the use of fluorescent dye-labeled probes against a nucleotide sequence of DNA that is mapped or localized to a chromosome or intra-nuclear DNA to generate a fluorescence signal which in turn is visualized in situ by microscopy. The hybridization of the probe to the corresponding nucleotide sequence enables detection of the presence or absence of specific sequences, mapping of translocation break points, and determination of gene copy numbers.

As a diagnostic tool, FISH is widely used in clinical genetics, neuroscience, reproductive medicine, toxicology, microbiology, evolutionary biology, comparative genomics, cellular genomics and chromosome biology. It assists in identification of genetic abnormalities associated with prenatal diagnosis, cancer and mental retardation. Automated FISH diagnostic systems have been approved by the US FDA under the medical device stream, a mark of the maturity and reliability of the technique.

FISH is an important tool for pathologists to diagnose infectious disease and cancer. It also helps make treatment decisions. For example, BRCA1/2 status is an important cancer marker that aid treatment decisions and can be detected by FISH.

FISH Probes

In the FISH procedure, fixed tissue sections are pretreated to expose target DNA or mRNA sequences. An appropriately labeled probe is hybridized to the exposed target DNA or mRNA sequences in the cells. Subsequent stringent washing steps remove any probe that is non-specifically bound to the tissue section. Subsequently slides are mounted using DAPI/antifade and can be visualized under fluorescence microscope using appropriate filter set. BioGenex provides a wide range of FISH probes as well as automated systems.

Nucleic Acid Retrieval

Nucleic Acid Retrieval is an effective way of unmasking DNA in formalin-fixed, paraffin-embedded tissue sections using microwave heating. BioGenex’s Nucleic Acid Retrieval solution breaks the formalin-induced cross-linking bonds between DNA and proteins, as well as protein-protein cross-linking thereby allowing better penetration of probes and accessibility of DNA for binding. Nucleic Acid Retrieval (NAR-1) is recommended instead of Proteinase K when DNA targeting probes are used.

eFISH Visualization Kits

BioGenex eFISH Visualization kit is intended for use in a Fluorescence in situ Hybridization (FISH) procedure and is optimized for the detection of target nucleic acid sequence. It is designed for the specific fluorescence detection of fluorescent-labeled nucleic acid probes following hybridization to target DNA or RNA sequences.

Visualization kits are available for formalin-fixed, paraffin-embedded (FFPE) tissue sections and cell preparations. BioGenex visualization kits provide unsurpassed performance.

eFISHHisto kit:

The BioGenex eFISHHisto kit is a novel system for processing formalin-fixed, paraffin-embedded (FFPE) tissues. This kit contains reagents for pretreatment and post-hybridization stringency washes of the tissue. This kit is to be used for BioGenex eFISHiency FISH processing platforms Xmatrx® Infinity/ELITE, Xmatrx® NANO, and Xmatrx® MINI along with BioGenex eFISH probes.

eFISHCyto kit:

The BioGenex eFISH cytology kit is a novel system for processing of cytological/hematological specimens/smears/cells. This kit contains reagents for pretreatment and post-hybridization stringency washes of the tissue. This kit is to be used for BioGenex eFISHciency FISH processing platforms Xmatrx® Infinity/Elite, Xmatrx® NANO, and Xmatrx® MINI along with BioGenex eFISH probes.


DAPI Mounting Medium contains 4’,6-diamidino-2-phenylindole (DAPI), which fluoresces when bound to DNA and is used as a nuclear or chromosomal counterstain. DAPI produces a blue fluorescence when bound to DNA with excitation at about 360 nm and emission at 460 nm. DAPI Mounting Medium is a unique, stable formula for preventing photo-bleaching of fluorescent proteins and fluorescent dyes during microscopic examination of fluorescence in situ hybridization specimens. DAPI Mounting Medium is water-soluble and has been optimized to preserve fluorescence during long-term storage, if mounted slides are stored at 2-8 °C.

DAPI Mounting Medium does not solidify, but remains as liquid on the slide and can be stored without sealing. To seal the coverslips permanently onto the slides, apply nail polish or a plastic sealant around the perimeter. Mounted slides should be stored at -20 °C protected from light. After use, store the remaining DAPI Mounting Medium at -20 °C and protected from light.


As a one-stop shop provider of molecular pathology workstations and reagents, BioGenex offer a comprehensive suite of ancillary products to support our customers including enzymes for tissue processing, dewaxing and rehydrating reagents, buffers, microscope slides and coverslips, and pipette tips. These high-quality products are aimed at accelerating the generation of reproducible and reliable tissue staining results.