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Breen, Matthew, PhD. C.Biol. M.I.Biol
Associate Professor of Genomics
Metaphase and interphase FISH are ‘direct’ approaches that make use of chromosome-specific paints or single locus probes. These are powerful techniques that allow a rapid assessment of the gross numerical and structural characteristics of a cell, looking directly at the chromosomes of the tumor cells Tumor metaphase FISH requires the availability of viable cells from which to produce tumor chromosome preparations for analysis. Interphase FISH is able to make use of preserved cellular material and may thus be extended to include the use of paraffin embedded biopsy sections. In the examples below, the figure on the left shows the application of FISH of single locus probes (SLP) to determine the number of copies of three different chromosomes in a canine cancer metaphase spread. In this case the chromosome with a blue SLP is present as three copies and so the cell is trisomy for this chromosome. On the right hand side is an example of a five color FISH reaction, using chromosome paint probes, to identify the nature of multiple aberrant chromosome in a metaphase preparation of a canine tumor cell.