FISH with and Without COT1 DNA
Complex FISH probes comprising large spans of genomic DNA always contain a high amount of dispersed repetitive sequences hampering the visualization of specific signals. To overcome this problem, different approaches have been elaborated that depend on experiment type and probe quality. A classical way to suppress repetitive sequences is to use unlabelled competitor DNA (sheared total genomic DNA or repeated sequences enriched DNA fractions). Here we present two protocols—the first one describes a rapid COT DNA isolation and peculiarities of its use in different FISH experiments, and the second is elaborated for COT-free FISH with complex probes and is based on a special software tool for image enhancement.
KeywordsRepetitive DNA DNA reassociation kinetics Genome composition COT1-DNA
This work was supported by grant of RSF (№14-14-00275) to VAT and by Welcome Trust grant to WR.
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