I FISH Techniques, FISH Probes and Their Applications in Medicine and Biology - An Overview
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However, in many diagnostic queries related to genetic or congenital disorders and to many forms of cancer, a specific approach based on preselected probes is not feasible due to a lack of prior insight regarding
the genome region of interest.
The development of 24-color karyotyping and CGH remedies this
drawback of classic FISH techniques where an in situ hybridization experiment only allows for a limited fraction of the chromosome complement to
be analyzed. 24-color karyotyping and CGH thus represents the next generation of cytogenetic techniques which, like chromosome banding, overviews the whole genome but with far higher sensitivity.
The potential use of FISH techniques is so enormous that it is impossible in a comprehensive way to cover all areas, but in the following sections, some of the more recent and general applications of FISH technology will be briefly reviewed with emphasis on clinical cytogenetics and
tumor cytogenetics.
Molecular cytogenetics as a diagnostic tool in clinical cytogenetics and oncology
The vast majority of chromosome analyses in clinical cytogenetics and in
oncology are still performed as an analysis of banded metaphases. These
banding techniques have not changed much over the past two decades
with the result that the minimum size of chromosome material that
can be detected, either lost or gained, by banding techniques has not changed very much either. This has left the impression in some quarters, that
chromosome analysis in the field of cytogenetics is obsolete and should be
replaced by molecular methods based on peR and gel-analysis. This is,
however, far from true, since the standard banding technique is now supplemented with a broad set ofFISH-methods based on modern DNA-technology.
Which types of challenges in cytogenetics may optimally be solved by
application of FISH technology? The challenges can be divided into two
groups:
I. Characterization of specific chromosomal aberrations. The primary
goal of employing classic FISH techniques is now mainly analysis or
screening for known chromosomal abnormalities (from locus specific
events to whole chromosomes) either in a single- or in a multi-color approach.
With the development of the initial FISH techniques, it became possible to identify numerical and structural chromosomal abnormalities
using either centromere-specific probes or whole chromosome painting
27
However, in many diagnostic queries related to genetic or congenital disorders and to many forms of cancer, a specific approach based on preselected probes is not feasible due to a lack of prior insight regarding
the genome region of interest.
The development of 24-color karyotyping and CGH remedies this
drawback of classic FISH techniques where an in situ hybridization experiment only allows for a limited fraction of the chromosome complement to
be analyzed. 24-color karyotyping and CGH thus represents the next generation of cytogenetic techniques which, like chromosome banding, overviews the whole genome but with far higher sensitivity.
The potential use of FISH techniques is so enormous that it is impossible in a comprehensive way to cover all areas, but in the following sections, some of the more recent and general applications of FISH technology will be briefly reviewed with emphasis on clinical cytogenetics and
tumor cytogenetics.
Molecular cytogenetics as a diagnostic tool in clinical cytogenetics and oncology
The vast majority of chromosome analyses in clinical cytogenetics and in
oncology are still performed as an analysis of banded metaphases. These
banding techniques have not changed much over the past two decades
with the result that the minimum size of chromosome material that
can be detected, either lost or gained, by banding techniques has not changed very much either. This has left the impression in some quarters, that
chromosome analysis in the field of cytogenetics is obsolete and should be
replaced by molecular methods based on peR and gel-analysis. This is,
however, far from true, since the standard banding technique is now supplemented with a broad set ofFISH-methods based on modern DNA-technology.
Which types of challenges in cytogenetics may optimally be solved by
application of FISH technology? The challenges can be divided into two
groups:
I. Characterization of specific chromosomal aberrations. The primary
goal of employing classic FISH techniques is now mainly analysis or
screening for known chromosomal abnormalities (from locus specific
events to whole chromosomes) either in a single- or in a multi-color approach.
With the development of the initial FISH techniques, it became possible to identify numerical and structural chromosomal abnormalities
using either centromere-specific probes or whole chromosome painting