Fish Technology Services

Fish technology services are generally used in the early stages to understand gene or chromosome amplification, deletion, fusion, or breakage, and are suitable for prenatal diagnosis, postpartum genetic disease testing, tumor diagnosis, and prognosis evaluation. The sample sources are diverse: tissues, exfoliated cells, amniotic fluid, blood, and bone marrow can all be tested, and are not limited to fresh samples. Paraffin samples aged 2-3 years can also be tested.

FISH can also detect nucleic acids in tissue chips (currently commonly used to detect ncRNA: microRNA, lncRNA, circRNA), which can determine the expression and localization of nucleic acids in dozens or hundreds of specimens. It can be used to analyze the differential expression of nucleic acids between cancer and adjacent tissues, the correlation between nucleic acid expression and survival, the relationship between nucleic acid expression and tumor occurrence and development, and so on.

Fish Technology Service Experimental Process:

Fish Technology ServicesFlorescence In Situ Hybridization (FISH) is a technique that uses non radioactive fluorescence signals to detect in situ hybridization samples. It combines the high sensitivity and safety of fluorescence signals, the intuitiveness of fluorescence signals, and the high accuracy of in situ hybridization. Through in situ hybridization of fluorescently labeled DNA probes with the DNA of the test sample, the fluorescence signals are identified and counted under a fluorescence microscope, thereby detecting and diagnosing cell and tissue samples with chromosomal or gene abnormalities, providing accurate basis for the typing, prediction, and prognosis of various gene related diseases. Since the late 1980s, when Pinkel and Heiles introduced FISH technology into the field of chromosome detection, FISH technology has been widely used in clinical diagnosis and scientific research, demonstrating significant advantages compared to some traditional techniques.

Fluorescence in situ hybridization technologyFish Technology ServicesCompared with traditional immunohistochemistry (IHC), FISH has good stability and reproducibility. At present, immunohistochemistry is widely used in clinical diagnosis of tumors and other fields. The detection target of immunohistochemistry is disease-related proteins. Due to the significant influence of various factors on protein expression and conformation, such as acids, bases, and denaturing agents, the stability of detection conditions is crucial for the detection results. In addition, the judgment of immunohistochemical test results depends on the subjective judgment of the tester on the colorimetric results. For some weakly positive results, different testers are prone to differences. The above factors may all affect the doctor's final diagnosis of the condition.

Fluorescence in situ hybridization technologyFish Technology ServicesThe target is DNA in cells, and the dense double helix structure allows DNA to maintain its good condition over millions of years. Its structure is stable and not easily affected by environmental conditions, providing a good foundation for the stability of fluorescence in situ hybridization technology. In addition, the determination of fluorescence in situ hybridization results objectively quantifies the detection results through color judgment and signal counting of fluorescence. If the corresponding FISH operating system (such as Abbott Vysis' Hybrit hybridization instrument and VP2000 sample preprocessing system) and chromosome imaging system are used, the automation of the entire FISH operation can be achieved, minimizing the subjective factors of operators and testers and ensuring the accuracy of results.

PCR is a widely used genetic diagnostic technique in recent years due to its high sensitivity and easy operation. However, the proportion of false negatives and false positives in PCR diagnostic technology is relatively high, and the same sample can only be analyzed once, so the experimental results cannot be repeated. With the continuous development of probe technology, the sensitivity of FISH has approached or reached the level of PCR, and can effectively compensate for the limitations of PCR technology. The fluorescence in situ hybridization technology for fish detection not only has a very low proportion of false positives and false negatives (taking Abbott Vysis' prenatal diagnostic probe as an example, the accuracy of 29000 cases has been confirmed to be as high as 99.9%), but also can perform multiple FISH operations on the same sample and use different colored fluorescent probes to detect abnormalities in multiple chromosomes or genes at once, greatly saving detection time. In addition, throughFish Technology ServicesDiagnostic research can be conducted on abnormalities in the number of chromosomes or specific genes, as well as deletions, translocations, and rearrangements of specific fragments.

Fluorescence in situ hybridization (FISH) technology is a method that uses non radioactive fluorescent substances to display the position of DNA sequences in the nucleus or chromosome based on the principle of nucleic acid probe hybridization. This technology has the characteristics of speed, safety, high sensitivity, and long-term preservation of probes. It has been widely used in fields such as cytogenetics, tumor biology, gene localization, gene mapping, gene amplification, prenatal diagnosis, and mammalian chromosome evolution research.

Simply put, it is the principle of complementary base pairing, which means that we pair exogenous nucleic acids (commonly known as molecular probes) with DNA or RNA to be detected on tissues or cells, forming nucleic acid hybrid molecules, and then display the position of this hybrid molecule through certain means.

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　　Fish Technology ServicesIt has been widely applied in fields such as cytogenetics, tumor biology, gene localization, gene mapping, gene amplification, prenatal diagnosis, and mammalian chromosome evolution research.

Fluorescence in situ hybridization simplifies the detection of chromosomal structural variations. The aneuploidy of plant chromosomes is caused by abnormal chromosome behavior, which may be due to differences in the number and structure of gamete chromosomes between parents or distant chromosomal relationships. In situ hybridization can easily detect missing, attached, or replaced chromosomes.

The spatial resolution and sensitivity of FISH enable the localization of parents and amplified genes in cells resistant to pests and diseases. The amplified genes are mainly located on the same chromosome arm, but at a certain distance from the initial parent gene, and often independently located at the telomere of the chromosome; FISH analysis suggests that cell breakage may be due to structural rearrangement of chromosomes containing amplified regions. At the same time, FISH can be used to locate the location and copy number of exogenous genes in transgenic plants, which has been successfully applied in crops such as tomato, tobacco, barley, wheat, and rye. FISH technology can also be used to detect gene deletions associated with genetic diseases, such as the successful detection of missing genes in patients with aniridia disease.

The gene localization technology of fluorescence in situ hybridization has a wide range of applications. Localization of PP2Ac mutant lung cancer-related genes in chromosomal regions, observation, recording, and analysis of hybridization signal characteristics under fluorescence microscopy. As a result, obvious hybridization signals were observed on chromosome 5q23-31 of normal human lymphocytes, and strong signals were observed on chromosomes 5 and 7 of GLC-82 cells. Point mutations cause changes in PP2Ac activity, leading to gene translocation and the development of lung tumors. The combination of FISH technology with biochemistry, computer, and recombinant DNA technology for detecting Alu sites indicates that DNA sequence is related to band type. The study of the distribution of coding genes in the human genome using FISH technology revealed that genes are mainly concentrated in the G+C (35% of the entire genome) DNA segment on chromosomes. FISH technology provides an important means for studying the structure of centromeres. The application of FISH technology allows for direct observation of chromosome telomeres, simplifying the study of chromosome structure and function within the nucleus.