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Molecular medicine Fluorescent In Situ Hybridization. A method for locating a segment of DNA on a chromosome. The DNA is labeled with a fluorescent dye and hybridized to a cytological preparation of chromosomes that has been denatured to allow nucleic acid hybridization between chromosomal DNA and the probe. The site of hybridization is determined by fluorescent microscopy. FISH is a hybrid of 3 technologies: cytogenetics, fluorescence microscopy, and DNA hybridization, which is used to determine cell ploidy and detect chromosome segments by evaluating interphase—non-dividing—nuclei; in FISH, fluoresceinated chromosome probes are used for cytologic analysis and cytogenetic studies, and to detect intratumoral heterogeneity. In genetics, FISH provides a physical mapping approach to detect hybridization of probes with metaphase chromosomes and with the less-condensed somatic interphase chromatin
DNA probes may be applied to cell preparations on a slide; if the complementary DNA sequence is present, it binds to DNA and can be detected by light microscopy; FISH labels probes nonradioactively either directly with fluorochromes, or indirectly with biotin and fluorochrome-labeled avidin, with digoxeginin and fluorochrome-labeled anti-digoxeginin, or others; the use of multiple band-pass filters allows simultaneous viewing of numerous probes for different chromosomal sequences labeled with different fluorochromes; FISH is useful in cytogenetic studies, where probes for particular chromosomes—e.g., chromosomes 13, 18, 21—or chromosomal regions—e.g., ABL and BCR genes in the Philadelphia translocation—can be used for the prenatal diagnosis of common aneuploidies or to detect early stages of lymphoproliferative disorders; FISH is as sensitive as other analytical techniques—e.g., conventional cytology and flow cytometry, used to diagnose transitional cell carcinoma of the urinary bladder
Pros FISH is simpler, less labor-intensive, and time-consuming—48 hours—than classic cytogenetics—karyotyping—2-3 weeks
Cons Only one question can be asked at a time, i.e., rather than asking ‘global issues’—e.g., what is the genetic composition of a population of cells
FISHFluorescent in situ hybridization Molecular medicine A hybrid of 3 technologies: cytogenetics, fluorescence microscopy, and DNA hybridization, which is used to determine cell ploidy and detect chromosome segments by evaluating interphase–non-dividing nuclei; in FISH, fluoresceinated chromosome probes are used for cytologic analysis and cytogenetic studies, and to detect intratumoral heterogeneity. See Chromosomal paint box.
FISHAbbrev for fluorescence in situ hybridization. This is a technique for detecting and locating gene mutations and chromosome abnormalities.
fishany of a large group of cold-blooded, finned aquatic vertebrates. fish are generally scaled, and respire by passing water over gills. fish were formerly placed in a single grouping, class Pisces. It is now recognised that there are four distinct classes, ACTINOPTERYGII, (ray-finned fishes), CHOANICHTHYES (fins with central skeletal axis - collectively sometimes classed as Osteichthyes, see BONY FISH) CHONDRYCHTHYES (sharks) and APHETOHYIDEAN (extinct, primitive, jawed fish).
FISHacronym for FLUORESCENCE IN SITU HYBRIDIZATION.
Patient discussion about FISH
Q. Does fish-oil helps exercise induced asthma? I was diagnosed with exercise induced asthma a couple of year ago, and since then had better and worse times with my asthma, although the treatment I get. I read in a newspaper that fish oil can help exercise induced asthma- is that true? Do I have to eat fish-oil specifically or can I eat fish instead (I really, really, hate fish-oil…)?
Q. Can omega-3 make my cholesterol lower? My doctor told me that I have too much cholesterol in my blood, and that it can cause heart attack or stroke, but if I keep it low than my risk will be lower. He told me that because it’s not that high level I can try to change my diet before I have to start taking medication. I heard that omega-3 can make my cholesterol level low. Is that true? Do I have to take it in pills? Is it safe?