Interphase Quantitative Fluorescence in Situ Hybridization (IQ-FISH)

Abstract

Fluorescence in situ hybridization (FISH) seems to be the most applicable and versatile molecular cytogenetic platform for interphase chromosome analysis offering a variety of opportunities for studying chromosomal structure and behaviour at the highest microscopic resolution and at all stages of the cell cycle. Quantitative assessment of FISH results has been repeatedly shown to increase the efficiency of FISH-based approaches. Here, we explore the potential of interphase quantitative FISH (IQ-FISH), which is the result of combining interphase FISH with an approach to FISH signal quantification. Firstly, IQ-FISH is applicable for high-resolution molecular cytogenetic analysis of somatic genome variations in large populations of interphase cells (n>>1000) inasmuch as it allows the differentiation between genomic variations (chromosome abnormalities) and specific nuclear chromosomal organization. Secondly, IQ-FISH may be a basis for more sophisticated interphase molecular cytogenetic techniques (i.e. multicolour banding of interphase chromosomes). Thirdly, IQ-FISH depicts nuclear organization by demonstrating the distribution of specific chromosomal DNA within a nuclear area. Finally, IQ-FISH is a unique technique allowing quantitative characterization of chromosomal heteromorphisms in interphase nuclei. It is to note that interphase chromosomal heteromorphisms are rarely evaluated because of technical limitations. In conclusion, IQ-FISH appears to be a handy technique to increase the efficiency of interphase chromosome analysis.