Fluorescence in situ hybridization (FISH) is a molecular cytogenetic technique that enables the detection and localization of specific DNA or RNA sequences within cells/tissues. DNA FISH is a very important tool not only for basic research, but also for clinical applications such as cytogenetic screening for diagnosis and prognosis of cancer (Oliveira and French 2005) and genetic syndromes (Volpi and Bridger 2008a), including prenatal screening. The principle of DNA FISH is to hybridize small single stranded DNA molecules (probes) to complementary sequences on chromosome spreads or in nuclei of whole cells (target), which are immobilized on glass slides. The probes are labeled directly or indirectly using fluorescent or radioactive nucleotides or through fluorescent antibodies (Volpi and Bridger 2008b). After labeling, FISH probes and targets are thermally denatured and hybridized.

The standard FISH technique, however, often suffers from limitations, namely poor signal to background noise ratio due to unspecific binding of probes to only partially complementary sequences or other cellular and tissue structures. In addition, while even routine in situ detection highly benefits from densely labelled, sensitive probes, the labelling rate of FISH probes generated by traditional methods is typically low.

baseclick’s ClickTech DNA FISH Kit overcomes these limitations and provides all reagents required for the generation of highly labelled FISH probes via an easy-to-handle method based on click chemistry. During enzymatic PCR synthesis, unmodified (dNTPs) and alkyne modified- (EdUTP) nucleotides are used by our baseclick Ethynyl Polymerase, producing a clickable PCR product (DNA FISH probe). By using click reagents (incl. in the kit) and a clickable dye (incl. in the kit) of your choice (green 488, yellow 555, orange 594 or red 647) you obtain DNA fluorescent labeled DNA FISH probes.