Molecular markers
Fluorescent in situ hybridization (FISH)
FISH general

Author: Rodney E. Shackelford, D.O., Ph.D. (see Authors page)

Revised: 30 May 2018, last major update April 2012

Copyright: (c) 2003-2018,, Inc.

PubMed Search: FISH[TI] general[TI]

Cite this page: Shackelford, R.E. FISH general. website. Accessed December 12th, 2018.
Definition / general
  • Used to visualize chromosomal deletions, amplifications, structural rearrangements and to identify whole chromosomes
  • Relative ease of sample preparation and analysis, high specificity, no requirement that the cells analyzed be activity dividing, can be performed on formalin fixed, paraffin embedded samples (allowing comparison of probe hybridization patterns to histology)
  • Prenatal diagnosis and genetic counseling, oncology (especially chromosomal translocations), basic research, gene mapping, species identification of pathogens
Specimen types
  • Solid tumors, bone marrow aspirates, peripheral blood (lymphocytes), amniotic fluid (amniocytes), skin (fibroblasts), chorionic villi
  • Uses interphase cells (noncultured) or cultured cells in metaphase (culture + colcemid to block cells in metaphase)
  • FISH development followed development of cytogenetics
  • 1882: Walther Flemming published the first illustrations of human chromosomes
  • 1956: Identification of 46 human chromosomes
  • 1959: Identification of trisomy 21 in Down syndrome
  • 1959: Identification of XXY in Klinefelter syndrome (Nature 1959;183:302)
  • 1959: Identification of XO in Turner syndrome (Lancet 1959;1:711)
  • 1960: Identification of Philadelphia chromosome in chronic myelogenous leukemia (J Clin Invest 2007;117:2033)
  • 1960s: Karyotype analysis now common, particularly with advent of dyes that reveal banding patterns specific to each chromosome pair
  • Later: Radiolabeled probes used to bind to specific chromosomal sequences, leading to first molecular cytogenetic analyses of human tissue
  • FISH became common after development of fluorescent labeled nucleic acid probes
  • Currently 1 million+ cytogenetic analyses performed worldwide every year
  • FISH can be performed on tissue imprints, cytopreps or bone marrow aspirate smears (J Clin Pathol 2005;58:629)
  • Ultrasound decalcification may allow more successful FISH, PCR and RT-PCR (Am J Surg Pathol 2006;30:892)
  • FISH can establish dizygotic origin of twin pregnancies if there are gender differences (Hum Pathol 1995;26:1175)