Genetics: Analysis and Principles 5th Edition by Robert Brooker

Exercise 19

Figure 22.2 describes the technique of FISH. Why is it necessary to "fix" the cells (and the chromosomes inside of them) to the slides What does it mean to fix them Why is it necessary to denature the chromosomal DNA
FIGURE 22.2 The technique of fluorescence in situ hybridization (FISH). The probe hybridizes to the denatured chromosomal DNA only at specific, complementary sites in the genome. Note that the chromosomes are highly condensed metaphase chromosomes that have already replicated. These are sister chromatids. Therefore, each X-shaped chromosome actually contains two copies of a particular gene. Because the sister chromatids are identical, a probe that recognizes one sister chromatid will also bind to the other.