Fluorescent In Situ Hybridization (FISH) Service

Fluorescence in situ hybridization (FISH), developed in the 1980s, is a cytogenetic technique using fluorescent probes to bind the chromosome with a high degree of complementarity. It is a powerful and easy method to detect RNA or DNA sequences in cells, tissues, and tumors. This technique is useful for identifying chromosomal abnormalities, gene mapping, characterizing somatic cell hybrids, checking amplified genes and studying the mechanism of rearrangements. RNA FISH is used to measure and localize mRNAs and other transcripts within tissue sections or whole mounts.

Scheme of the principle of the FISH experiment to localize a gene in the nucleus.Fig. 1 Scheme of the principle of the FISH experiment to localize a gene in the nucleus.

FISH is useful, for example, to help a researcher or clinician identify where a particular gene falls within an individual's chromosomes. The first step is to prepare short sequences of single-stranded DNA that match a portion of the gene the researcher is looking for. These are called probes. The next step is to label these probes by attaching one of a number of colors of fluorescent dye. DNA is composed of two strands of complementary molecules that bind to each other like chemical magnets. Since the researchers' probes are single-stranded, they are able to bind to the complementary strand of DNA, wherever it may reside on a person's chromosomes. When a probe binds to a chromosome, its fluorescent tag provides a way for researchers to see its location.

Fluorescent In Situ Hybridization

Application of FISH

Scientists use three different types of FISH probes, each of which has a different application:

Locus Specific Probes bind to a particular region of a chromosome. This type of probe is useful when scientists have isolated a small portion of a gene and want to determine on which chromosome the gene is located, or how many copies of a gene exist within a particular genome.

Alphoid or Centromeric Repeat Probes are generated from repetitive sequences found in the middle of each chromosome. Researchers use these probes to determine whether an individual has the correct number of chromosomes. These probes can also be used in combination with "locus specific probes" to determine whether an individual is missing genetic material from a particular chromosome.

Whole Chromosome Probes are actually collections of smaller probes, each of which binds to a different sequence along the length of a given chromosome. Using multiple probes labeled with a mixture of different fluorescent dyes, scientists are able to label each chromosome in its own unique color. The resulting full-color map of the chromosome is known as a spectral karyotype. Whole chromosome probes are particularly useful for examining chromosomal abnormalities, for example, when a piece of one chromosome is attached to the end of another chromosome.

Human chromosome X paint ProbeFig 2. Human chromosome X paint Probe

Sheep Specific Gene ProbeFig 3. Sheep Specific Gene Probe

Human Telomere FISH ProbeFig 4. Human Telomere FISH Probe

Creative Bioarray offers a range of different FISH services including:

  • Metaphase and Interphase FISH (chromosomal assignment and clone ordering)
  • Fibre-FISH (Chromosome Painting)
  • RNA-FISH (cell-based gene expression assay)
  • M-FISH (multicolour karyotyping)
  • 3D-FISH (on three-dimensionally preserved nuclei )
  • Flow-FISH (quantify the length of telomeres)
  • FISH on paraffin sections (analysis of archive material)
  • ImmunoFISH (combined FISH and IHC)

With combined academic and industrial experiences, we are confident that we will achieve high quality work and guarantee you complete satisfaction. As an important routine technique, FISH could be very time consuming. Creative Bioarray fully understands the details and pitfalls of FISH and histology. We will work side-by-side with you to find the best design to achieve your aims. Our service is efficient and reliable with relatively low cost.

Quotation and ordering

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