Fiber FISH as a DNA Mapping Tool
Fluorescence in situ hybridization (FISH) applied to metaphase chromosomes provides a mapping resolution of 1 to 3 Mb. FISH applied to interphase nuclei has a resolution of 50 kb and ranges 1-2 Mb. This better resolution is attributed to the higher degree of chromatin decondensation. Here, we describe FISH applied to naked DNA fibers (fiber FISH) and show that with such fully decondensed chromatin a resolution range of at least 1-400 kb can be obtained. Furthermore, we show that DNA fiber FISH provides a mapping tool that is highly supplementary to restriction mapping, because it permits very accurate gap and overlap sizing. Also, DNA fiber FISH provides the means to generate "color bar codes" for disease regions, which can be used to inspect patient DNAs for suspected gene rearrangements.
Raap
AK
Department of Cytochemistry and Cytometry, Leiden University, Wassenaarseweg 72, Leiden, NL 2333 AL, The Netherlands
Florijn
RJ
Blonden
LAJ
Wiegant
J
Vaandrager
JW
Vrolijk
H
den Dunnen J
Tanke
HJ
van Ommen GJ