“…In general, after the restriction enzyme recognizes, cleaves and removes determined DNA sequences from fixed chromosomes or interphase chromatin, specific images are generated (Mezzanotte et al, 1983;Bianchi et al, 1986;Sentis et al, 1989;Gonsálvez et al, 1995;Mello et al, 2000). The richness in -CCGG-sequences excised by Msp I/Hpa II, and the presence of methylated CpG sequences not cut by Hpa II, can be evaluated by quantifying the response to the Feulgen reaction, specific for DNA, under the action of these enzymes, using video or microspectrophotometric image analysis (Mello et al, 2000(Mello et al, , 2009bMampumbu and Mello, 2006).…”