FISH or Fluorescence in situ Hybridization is a popular tool in the diagnostic market. It is often used as a diagnostic technique for patients undergoing infertility treatment, as well as for determining the number of chromosome in embryos used for research. FISH is used for the detection of RNA or DNA sequences in cells, tissues and tumors. Several methodologies have been developed to improve the detection of DNA and RNA.
However, FISH has proved to have a very wide range of applications and is not very difficult to implement. Moreover, this technique is a useful bridge between cytogenics, cell biology and molecular genetics.
FISH: An Advanced Diagnostic Tool
The foundation of the technology remains the same as it was two decades ago. However, the diagnostic tool has made significant advancements with the use of automated data collection techniques, as well as employment of high-sensitivity detection.
How does it work
In this technique, in which single-stranded nucleic acids are allowed to interact so that molecules with similar or complementary sequences form hybrids or complexes. This hybridization helps determine the degree of sequence identity. Moreover, this also leads to detection of specific sequences on a particular chromosome.
There are three basic steps involved:
- A specimen is fixed on a microscope slide
- The probe is allowed to hybridize
- Finally, the enzymes of the target are then detected.
Non-isotopic techniques are more popular in the diagnostic market these days, with fluorescent hybridization being the preferred mode. The reason for this is the faster protocols that non-isotopic probes allow. Moreover, it also allows for a combination of detection methods with high signal resolution.
Applications of the FISH Diagnostic Tool
ISH has a variety of applications in the field of molecular biology, including the diagnosis of chromosomal abnormalities and gene mappings. This diagnostic tool is also used in clinical research for prenatal diagnosis of inherited chromosomal aberrations and postnatal diagnosis of carriers of genetic disease. The technique is also used for diagnosing infectious diseases, both viral and bacterial. High resolution FISH is a very popular method for ordering genes or DNA markers.
The Future of the Technology
Developed in 1980s, this technology continues to remain the foremost biological assay. Advancements in the methodology have ensured that the diagnostic tool continues to be used for low noise hybridization probes. Moreover, with technological developments, FISH now permits quantitative analysis and multi-target visualization. The diagnostic tool is now used for investigation of nucleic acids for several purposes and is widely available. The future seems bright for this technique, given that it is expected to make further contributions to medical diagnostics and live-cell imaging.