This probe enabled facile identification of all chromosome pairs in mitotic chromosome spreads. Paraffin-embedded, frozen tissue and cultured cells are used for FISH analysis, besides this, both types of cells (non-dividing as well as dividing cells) are applicable in FISH. For making hybridization possible, we need to denature the sample so that our probe can bind to the DNA sequence. Fluorescence in situ hybridization (FISH) is a cytogenetic technique used to detect the presence or absence and location of specific gene sequences. Any chromosomal anomalies like deletion or duplication of the gene of our interest can be encountered using the locus-specific probe. Prepare the slide with the cell suspension. If needed repeat the washing step followed by DAPI counterstain. The pictorial illustration of the whole chromosome probe, repeat sequence probe, and locus-specific probe used in FISH. (�� Add 30µl of hybridization solution on a slide, heat it at 65 to 70. Wash the slide as instructed by the manufacture. Multiple locus-specific probes are used for the detection of multiple DNA sequences on different chromosomes. CGH used for quantitative detection of copy number variations. The karyotyping takes at least 3 to 4 days to complete the entire process while the FISH method is rapid, one can get results within a day. Note: a special type of FISH applied for the temporary gene expression pattern within cells by using the RNA as the template for the FISH. After the sample is prepared, the probe mixture is applied on the surface of the glass slide having the sample. Figure 2. histology and dual-target fluorescence in situ hybridization (Fish) with probe rmc11B022 for c hromosome 11p and rmc11p008 for chromosome 11q. In Situ Hybridization (ISH) is a technique that allows for precise localization of a specific segment of nucleic acid within a histologic section. It can visualize specific cytogenetic abnormalities (copy number aberrations) such as chromosomal deletion, amplification, and translocation. Fixation of the cells of interest before FISH is a critical step in the analysis process. Materials Required but Not Supplied Ethanol Purified water (deionized or distilled) Acetic acid and methanol Rubber cement C for 10 minutes and cool it by placing it on ice. �O�P|"$����+� � A fluorescence microscope is needed though. <>/PageLabels 323 0 R>> The unbound probes are washed off to avoid unwanted signals from the site of hybridization. COMBO-FISH stands for combinatorial oligonucleotide FISH used for the detection of homopurine or homopyrimidine region of the genome. Take a look at the figure to know how different probes work. COMBO-FISH stands for combinatorial oligonucleotide FISH used for the detection of homopurine or homopyrimidine region of the genome. We have covered an article on gene mapping. The technique relies on exposing chromosomes to a small DNA sequence called a probe that has a fluorescent molecule attached to it. In the present article, we are going to learn about one of the molecular cytogenetic techniques; Fluorescent in situ hybridization. In situ hybridization is a technique that is used for localization and detection of specific DNA and RNA sequences in cells, preserved tissue sections, or entire tissue (whole mount in situ hybridization, Fig. In the next step, the slide is incubated for 12 hours for hybridization to occur. Generally, the direct labeling method is used for probe generation, in which the fluorophores are directly attached to the nucleotides. Select the target sequence: if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-box-4-0')};if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-box-4-0_1')}; .box-4-multi-112{border:none !important;display:block !important;float:none;line-height:0px;margin-bottom:7px !important;margin-left:0px !important;margin-right:0px !important;margin-top:7px !important;min-height:250px;padding:0;text-align:center !important;}. For making hybridization possible, we need to denature the sample so that our probe can bind to the DNA sequence. Using the chromatin fiber or DNA fiber, the high-resolution gene mapping can be done using the Fiber-FISH method. Add 30µl of hybridization solution on a slide, heat it at 65 to 70°C for 10 minutes and cool it by placing it on ice. The locus-specific probes are used to determine the location of the isolated gene and to quantify that gene within a genome. Wash the slide with 2X SSC for 4 to 5 minutes, followed by 10mM HCL rinsing. Figure 1. schematic diagram of the fluorescence in situ hybridization (Fish) technique. The user of the system specifies classes of a class network and process steps of a process hierarchy. Contrary, the fluorescence in situ hybridization method is rapid and the chance of contamination is negligible. One of them is the comparative genomic hybridization. Over its maturation,various methodologies and modifications have been introduced to optimize the detection of DNA and RNA. Read our article on preparing probes: DNA Probes: Labelling, Types And Uses. Add antibody to the slide and incubate it for an hour and with it with 2X SSC buffer. This unusual triplet structure is located using the fluorescent signals having the homopurines or homopyrimidines, this information is used for the 3-D (three-dimensional) study of the human genome. The locus-specific probes are used in the study of a particular gene or DNA sequence of interest. if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-large-mobile-banner-1-0')};if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-large-mobile-banner-1-0_1')}; .large-mobile-banner-1-multi-116{border:none !important;display:block !important;float:none;line-height:0px;margin-bottom:7px !important;margin-left:0px !important;margin-right:0px !important;margin-top:7px !important;min-height:250px;padding:0;text-align:center !important;}. A computation tool used for the prediction of the outcome of the FISH experiment is called electronic FISH. If cells are not dividing, we can not culture it using the. �fF%�%��� �� �x��A�]*Oc)%V�i���w�gSzGaF�T��W2l�2 Another advantage of FISH is it allows the analysis of the nondividing cells such as solid tumor cells. On the other side, the cytogenetic techniques are used for the detection of chromosomal anomalies or abnormalities. The probe hybridization is done directly on the glass slide containing the chromatin fibers. It is used in gene and genetic mapping. Fluorescence in Situ Hybridization is the most frequently used technique of PGD, and can analyze the chromosomes that make up the embryo. one of them is the precision. A higher degree of a sequence-complementary DNA or RNA probe is hybridized on a chromosome, in a cell using chemical treatments. Fluorescence in situ hybridization (FISH) Chromosomes Chromosomes are structures that contain the genetic information (DNA) that tells the body how to develop and function. Since current manual FISH signal analysis is low-efficient and inconsistent, which limits its clinical utility, developing automated FISH image scanning systems and computer-aided detection (CAD) schemes … Fluorescence In Situ Hybridization: Uses and Limitations Alessandro Gozzetti andMichelle M. Le Beau The development of molecular hybridization techniques such as fluorescence in situ hybridization (FISH) has had a major impact on efforts to detect and characterize the genetic changes that give rise to human tumors. Fluorescence in situ hybridization (FISH), the assay of choice for localization of specific nucleic acids sequences in native context, is a 20-year-old technology that has developed continuously. One of the most fascinating applications of quantitative FISH is in the monitoring of disease progression. A. higher temperature or denaturing agents are used for generating single-stranded target DNA for hybridization. Interestingly, for performing the fiber-FISH, the chromatin fibers are extracted and stretched on a slide using the fluid-flow method. %PDF-1.5 Cell culture process is not needed for performing FISH which is one of the most important advantages of it. The whole principle is graphically explained here. have allowed the increasingly sensitive detection of chromosome abnormalities in haematological malignancies, At present, it is routinely used in preimplantation genetic diagnosis (PGD). FISH (Fluorescent In Situ Hybridization) is generally performed on stimulated peripheral blood for both chromosomal analysis and the identification of specific translocation and deletion. In the FISH, “The nucleotide sequence can be mapped or detected using the fluorescent probes complementary to the sequence located on chromosome in a cell under the fluorescent microscope from the biological specimen.”. Using conventional cytogenetic methods like karyotyping chromosomal abnormalities can be encountered. This method is based on the complementary binding of a nucleotide probe to a specific target sequence of DNA or RNA. Fluorescent in situ hybridization, or 'FISH' is a technique used in molecular microbiology to identify bacteria within formalin fixed tissues. stream Fluorescence in situ hybridization (FISH) tests provide promising molecular imaging biomarkers to more accurately and reliably detect and diagnose cancers and genetic disorders. 1) by hybridizing the complementary strand of a nucleotide probe to a particular sequence. These probes can be labeled with either radio‐, fluorescent‐, or antigen‐labeled bases. I strongly recommended learning basic karyotyping. An analysis system automatically analyzes and counts fluorescence signals present in biopsy tissue marked using Fluorescence in situ Hybridization (FISH). Using conventional cytogenetic methods like. Broadly, it is used in the characterization of different chromosomes and numerical chromosomal abnormalities. In the present article, we are going to learn about one of the molecular cytogenetic techniques; Fluorescent in situ hybridization. For example, the GTG banding is used in the detection of numerical chromosomal anomalies while NOR banding is used for the detection of trisomy 21. (�� The interpretation part required one fold lesser expertise. The karyotyping takes at least 3 to 4 days to complete the entire process while the FISH method is rapid, one can get results within a day.if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-medrectangle-4-0')};if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-medrectangle-4-0_1')}; .medrectangle-4-multi-111{border:none !important;display:block !important;float:none;line-height:0px;margin-bottom:2px !important;margin-left:0px !important;margin-right:0px !important;margin-top:7px !important;min-height:250px;padding:0;text-align:center !important;}. When DNA on the chromosome are denatured, the fluorescently labeled complementary DNA probes hybridize with it and emits fluorescence, consequently. The DNA is denatured using heat or alkaline agents. Single-molecule RNA-FISH is employed for the quantification of gene expression from the tissue sample, using the hybridization method. It is a mixture of probes that binds to the entire chromosome length and thus different chromosomes are colored or labeled with different colored probes. Interphase or metaphase chromosomes are the best choice for performing FISH efficiently. By using the variation like SKY and M-FISH, new non-random genetic abnormalities can be identified as well. After that, the results are analyzed under the fluorescent microscope. This lesson touched on the basis of an in situ hybridization. Fluorescence microscopycan be used to find out where the fluorescent probe is bound to the chromosomes. The locus-specific probes are used to determine the location of the isolated gene and to quantify that gene within a genome. C and block it in a blocking buffer for 30 minutes. Note: different probes are nowadays available for different chromosomal anomalies, probe designing is not required for performing any FISH experiment. 2 0 obj Fluorescence in situ hybridization (FISH) is the technique of choice for preimplantation genetic diagnosis (PGD) selection of female embryos in families with X-linked disease, for which there is no mutation-specific test. endobj �� 7{" �� Known as quantitative FISH used for the quantification of the genetic material hybridized by the probe. Also, a specific breakpoint at where the translocation occurs can be determined. Illustration of two different color probe hybridized at two different locations on a chromosome. The protocol is originally adopted from Sigma-Aldrich. It is a BLAST-based program that utilizes the sequence information for, Using the chromatin fiber or DNA fiber, the high-resolution. Identification of specific chromosomal abnormality especially structural as well as numerical; chromosomal deletion, duplication, and translocation can be detected using the fluorescence in situ hybridization. FISH is a ‘molecular cytogenetic technique‘ in which using the molecular probes, any type of chromosomal abnormalities can be encountered precisely by hybridization. Known as quantitative FISH used for the quantification of the genetic material hybridized by the probe. Place the slide in the paraformaldehyde solution for 5 to 10 minutes for fixing and wash it with the same SSC buffer. The homopurine and homopyrimidines cover approximately 2% of the human genome. In the next step, the slide is incubated for 12 hours for hybridization to occur. A fluorescent probe that binds to bacterial ribosomes in tissue sections can be visualized using a fluorescent microscope. The whole chromosome probes are used for the multi-color FISH and spectral karyotyping. Although potentially a powerful technique, FISH studies for aneuploidy can be heavily influe … Related article: Genetics Basics: A Beginners Guide To Learn Genetics. The karyotyping method relies on the banding techniques to find out any aberrations. µl RNAse solution for 1 hr at room temperature. Learn vocabulary, terms, and more with flashcards, games, and other study tools. �� � } !1AQa"q2���#B��R��$3br� The whole chromosome probes are used for the multi-color FISH and spectral karyotyping. 1 0 obj The homopurine and homopyrimidines cover approximately 2% of the human genome. The fluorescent intensity is measured for quantification thus it is used in the study of telomere and aging, cancer and gene expression. Fluorescent in Situ Hybridization Probe Market Professional Survey Report 2018 - Fluorescent in Situ Hybridization Probe market status and forecast, categorizes the global Fluorescent in Situ Hybridization Probe market size (value & volume) by manufacturers, type, application, and region. An analysis system automatically analyzes and counts fluorescence signals present in biopsy tissue marked using Fluorescence in situ Hybridization (FISH). Image credit: Evelin Schröck, Stan du Manoir, Thomas Ried. The technique was developed in the year 1980. The probe is a single-stranded sequence of DNA or RNA complementary to our gene of interest. It is used in the analysis of numerical chromosomal anomalies like monosomy, disomy and trisomy. Read our series of articles on cytogenetics: The karyotypinghub is a place to learn karyotyping and cytogenetics: Buy our eBook “From DNA extraction to PCR” from here: © 2020 Genetic Education Inc. All rights reserved. Fluorescence in situ hybridization (FISH) is a kind of cytogenetic technique which uses fluorescent probes binding parts of the chromosome to show a high degree of sequence complementarity. The DNA is a double helical structure and more stable. 5 0 obj Read our previous article on cytogenetics: A Brief Introduction To Cytogenetics [Karyotyping, FISH and Microarray]. The tagging of fluorophores on the nucleotide sequence can be done using either the nick translation method or PCR. Microfluidics- associated FISH uses microfluidics for improving the performance of the FISH. The DNA is a double helical structure and more stable. The conventional karyotyping method is tedious and time-consuming, required a higher degree of expertise to interpret the results. It is a BLAST-based program that utilizes the sequence information for in silico estimation of the hybridization process. Scientists visualize the slide under the fluorescent microscope, if the probe hybridized properly on its complementary sequence, it emits two fluorescent signals. Paraffin-embedded tissues, FFPE tissues, tumor cells, cell culture, or chromosomal suspension are some common sample types used to do this.if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-leader-1-0')};if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-leader-1-0_1')}; .leader-1-multi-115{border:none !important;display:block !important;float:none;line-height:0px;margin-bottom:7px !important;margin-left:0px !important;margin-right:0px !important;margin-top:7px !important;min-height:250px;padding:0;text-align:center !important;}. It is used in the analysis of numerical chromosomal anomalies like monosomy, disomy and trisomy. The cell culture takes more time, approximately 3 to 4 days and the chance of contamination is higher as well. Fluorescence microscopy can be used to find out where the fluorescent probe bound to the chromosome. Fluorescence in situ hybridization (FISH) is a widely accepted approach to the analysis of the chromosomal complement in cells. <> The probes are fluorescently labeled, once it finds its complementary sequence (which is a sequence of our interest), it emits the fluorescent which we can observe under a microscope. The molecular cytogenetic technique facilitates several benefits over the traditional cytogenetic method. The DNA is a stable duplex, under normal conditions hydrogen bonding between two strands (two between adenine and thymine; and three between cytosine and guanine) makes it stable. Once hybridization completes, we need to wash the slide in order to wash off partially and incompletely hybridized probes. Fluorescence in situ hybridization - RNA is labeled with fluorescent probes Lesson Summary. (a) Case 2, normal CGH measurement; (b) case 13, , fluorescence in situ hybridization (FISH) ( flōr-es'ĕnt in sit'ū hī'brid-ī-zā'shŭn, flōr-es'ĕns) A method used to determine the chromosomal location or expression pattern of genomic DNA or cDNA fragments. In situ hybridization (ISH) is used to visualize defined nucleic acid sequences in cellular preparations by hybridization of complementary probe sequences. The fluorescent probes are nucleic acid labeled with fluorescent groups and can bind to … The hybridization is visualized under the fluorescent microscope. if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-leader-4-0')};if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-leader-4-0_1')}; .leader-4-multi-120{border:none !important;display:block !important;float:none;line-height:0px;margin-bottom:7px !important;margin-left:0px !important;margin-right:0px !important;margin-top:7px !important;min-height:250px;padding:0;text-align:center !important;}. Mar 05, 2021 (Heraldkeepers) -- The base year considered for the study is 2019, and the market size is projected from 2020 to 2026. Interphase or metaphase chromosomes are the best choice for performing FISH efficiently. The method is a type of RNA-FISH used to study the neurons associated with abnormal cognitive behavior. 3 0 obj The probe is a single-stranded sequence of DNA or RNA complementary to our gene of interest. Abstract. Here, instead of DNA, RNA is used as a target for probe hybridization. Once the target sequence is selected, based on the data of the sequence we wish to study, the probe is designed. endobj 9 Fluorescence In Situ Hybridization (FISH) 9.1 Summary of FISH. Thus it is widely used in the gaps and overlap fragment analysis, assessment of duplication and other copy number variation detection which can not be detected by the conventional FISH method. Although FISH is a highly versatile and rapid method, one should learn the basic chromosome preparation and karyotyping methods to boost their knowledge and expertise. The polynucleotide chain which we are utilizing as a probe is then labeled with the fluorophores. stream The cross-reactivity rate of the FISH probes is also very low. %&'()*456789:CDEFGHIJSTUVWXYZcdefghijstuvwxyz��������������������������������������������������������������������������� Thus it is widely used in the gaps and overlap fragment analysis, assessment of duplication and other copy number variation detection which can not be detected by the conventional FISH method. Then pixel values in image slices of biopsy tissue are acquired in three dimensions. (A) Schematic diagram of the superior resolution offered by fluorescence in situ hybridization (FISH). The result of multicolor FISH illustrating the different colors of chromosomes. $4�%�&'()*56789:CDEFGHIJSTUVWXYZcdefghijstuvwxyz�������������������������������������������������������������������������� ? The karyotyping method is entirely based on the chromosome banding thus it is restricted, using multiple probes in FISH multiple hybridization sites have been analyzed using different fluorophores. Rinse slide with distilled water and then with 2x SSC. endstream The karyotyping method is entirely based on the chromosome banding thus it is restricted, using multiple probes in FISH multiple hybridization sites have been analyzed using different fluorophores. Cover the slide with a coverslip and again heat it 65 to 70. The hybridization is visualized under the fluorescent microscope. tion. endobj “By hybridizing the fluorescently labeled probe to the complementary DNA sequence, the position of DNA sequence can directly locate on a chromosome. For example, it is used to demonstrate Philadelphia chromosome (Ph 1 ) formed by the translocation between chromosome 9 and 22 and causes a chronic myelogenous leukemia (CML). Fluorescence in situ hybridization with chromosome-specific DNA probes is being increasingly utilized for the detection of chromosome aberrations induced in vitro and in vivo by chemical and physical agents. Any chromosomal anomalies like deletion or duplication of the gene of our interest can be encountered using the locus-specific probe. The DNA is denatured using heat or alkaline agents. The technique is an advanced version of the cytogenetic analysis used in gene mapping, identification of major deletion or copy number variations, disease diagnosis, medicines, and species identification. The FISH method is based on the phenomenon of the denaturation and renaturation of DNA duplex. In the very first step, before doing any wet lab work we have to select the sequence or the portion of a chromosome we wish to study. µl pepsin and incubate for 8 to 10 minutes at room temperature. Centromere probes, locus-specific probe, whole chromosome probe and telomere probes are some of the examples of it. (��2�a����K}�4� ��ǦS�W��:ޭ}rg��.��!U_� so in this video we're going to be talking about something known as DNA hybridization Tignes hybridize alright so in this video we're going to be talking about something known as DNA hybridization DNA hybridization now what is DNA hybridization well basically what it so let's work through an example to try and explain what DNA hybridization is so let's imagine that we have two … Ratan ZA, Zaman SB, Mehta V, Haidere MF, Runa NJ, Akter N. Application of Fluorescence In Situ Hybridization (FISH) Technique for the Detection of Genetic Aberration in Medical Science. Multiple locus-specific probes are used for the detection of multiple DNA sequences on different chromosomes. The fluorescent intensity is measured for quantification thus it is used in the study of telomere and aging, cancer and gene expression. Start studying FLUORESCENT IN SITU HYBRIDIZATION. Fluorescence in situ hybridization (FISH) is a laboratory technique for detecting and locating a specific DNA sequence on a chromosome. Q-FISH: if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-leader-2-0')};if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-leader-2-0_1')}; .leader-2-multi-118{border:none !important;display:block !important;float:none;line-height:0px;margin-bottom:7px !important;margin-left:0px !important;margin-right:0px !important;margin-top:7px !important;min-height:250px;padding:0;text-align:center !important;}. The ACM-FISH is a variation of the multicolor FISH especially designed for the sperm cells. The technique was developed in the year 1980. Interestingly, for performing the fiber-FISH, the chromatin fibers are extracted and stretched on a slide using the fluid-flow method. Our slide is ready for hybridization. The DNA is a stable duplex, under normal conditions hydrogen bonding between two strands (two between adenine and thymine; and three between cytosine and guanine) makes it stable.if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-medrectangle-3-0')};if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-medrectangle-3-0_1')}; .medrectangle-3-multi-110{border:none !important;display:block !important;float:none;line-height:0px;margin-bottom:7px !important;margin-left:0px !important;margin-right:0px !important;margin-top:7px !important;min-height:50px;padding:0;text-align:center !important;}. Dual FISH could distinguish the phenomenon of multiple transcripts expressed in a single cell from the phenomenon of multiple proximal cells uniquely expressing transcripts that collectively mimic coexpression. Centromere probes, locus-specific probe, whole chromosome probe and telomere probes are some of the examples of it. Each pair contains a chromosome from each parent and … For example, the GTG banding is used in the detection of numerical chromosomal anomalies while NOR banding is used for the detection of trisomy 21. cocktail for simultaneous fluorescent in situ hybridization (FISH). The fluorescence in situ hybridization technique is capable of detecting larger copy number variation efficiently. Place the slide for some time to air dry. Examples of some commercially available probes for different FISH assays are given below. Fluorescence in situ hybridization (FISH) is a molecular cytogenetic technique that uses fluorescent probes that bind to only those parts of a nucleic acid sequence with a high degree of sequence complementarity. It is practiced for monitoring the success of transplantation, for example, bone marrow transplantation. Once the target sequence is selected, based on the data of the sequence we wish to study, the probe is designed. one of them is the precision. This unusual triplet structure is located using the fluorescent signals having the homopurines or homopyrimidines, this information is used for the 3-D (three-dimensional) study of the human genome. The piece of DNA to be mapped (the "probe") is labeled with a fluorescent dye and hybridized to a chromosome preparation or to a tissue section. The probes are designed to hybridize on these regions of the genome and create a triple helical structure with it by binding with the DNA duplex. In situ hybridization (ISH) is a type of hybridization that uses a labeled complementary DNA, RNA or modified nucleic acids strand (i.e., probe) to localize a specific DNA or RNA sequence in a portion or section of tissue or if the tissue is small enough (e.g., plant seeds, Drosophila embryos), in the entire tissue (whole mount ISH), in cells, and in circulating tumor cells (CTCs). It increases the hybridization efficiency as well as decreases the time consumption thus it is used in the bread cancer for detection of the HER2 gene mutation. if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-box-3-0')};if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-geneticeducation_co_in-box-3-0_1')}; .box-3-multi-109{border:none !important;display:block !important;float:none;line-height:0px;margin-bottom:7px !important;margin-left:0px !important;margin-right:0px !important;margin-top:7px !important;min-height:50px;padding:0;text-align:center !important;}. It is used for the detection of the role of the chromosomal damage in the development of infertility in males. Read our article on preparing probes: For various applications in various varients of FISH different types of probes are used. Fluorescence in situ hybridization (FISH) is a technique that uses fluorescent probes which bind to special sites of the chromosome with a high degree of sequence complementarity to the probes.