Use of DBD-FISH for the study of cervical cancer progression

Abstract

DNA breakage detection-fluorescence in situ hybridization (DBD-FISH) is a procedure to detect and quantify DNA breaks in single cells, either in the whole genome or within specific DNA sequences. This methodology combines microgel embedding of cells and DNA unwinding procedures with the power of FISH coupled to digital image analysis. Cells trapped within an agarose matrix are lysed and immersed in an alkaline unwinding solution that produces single-stranded DNA motifs beginning at the ends of internal DNA strand breaks. After neutralization, the microgel is dehydrated and the cells are incubated with fluorescently labeled DNA probes. The amount of hybridized probe at a target sequence correlates with the amount of single-stranded DNA generated during the unwinding step, which is in turn proportional to the degree of local DNA breakage. A general view of the technique is provided, emphasizing its versatility for evaluating the association between DNA damage and progressive stages of cervical neoplasia.