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In situ hybridization (ISH)

Related Terms

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Background

  • In situ hybridization (ISH) is a method that researchers may use to determine whether a specific part of a chromosome or a specific messenger RNA (mRNA) is present in a cell. Chromosomes are located in a compartment of the cell called the nucleus and are composed of deoxyribonucleic acid (DNA) and proteins. Human cells contain 46 chromosomes, including 22 pairs of autosomes and one pair of sex chromosomes, and each chromosome has hundreds of genes. Genes contain the instructions for making the proteins that do the work in the human body. Messenger ribonucleic acids (mRNAs) are molecules that are made from DNA and are used by the cell to produce proteins.
  • To perform ISH, researchers may first identify a specific region of a chromosome or the mRNA for a specific gene that they are interested in studying. They then generate a probe, which is a sequence of DNA or RNA that can recognize and bind to the chromosomal region or mRNA of interest. ISH that is used to detect DNA or a chromosome has the potential to provide evidence that a gene is present in a cell. Likewise, ISH that is used to detect mRNA also has the potential to provide evidence that a gene is actively being made in a certain cell.
  • A label is a type of molecule that researchers attach to a probe so they can determine whether the probe has identified the target DNA or mRNA. There are several different ways that a probe used for ISH can be labeled. Some probes are labeled, with a fluorescent substance so they emit a colored light if the target of interest is present in a cell. This procedure may be called fluorescent in situ hybridization, or FISH. Some probes are designed to generate a colored stain. Probes that produce a colored stain may be observed using a normal light microscope, whereas probes that give off fluorescent light need to be detected with a more expensive fluorescent microscope.
  • In some diseases, such as cancer, genetic mutations occur that can cause part of a chromosome to be deleted, repeated, or reversed in orientation. Also, in some diseases, specific mRNAs may be produced at higher or lower levels. By observing the differences in how chromosomes or mRNAs from different cells stain with a probe, a researcher may gain further insight into the genetic mutations that cause a particular disease.

Methods

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Research

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Implications

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Limitations

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Safety

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Future Research

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Author Information

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References

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

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The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.