Fluorescent probes of chromosomal DNA structure: three classes of acridines.

Abstract

Acridine dyes have been used extensively as fluorescent stains in cytological studies. Acridine orange has been particularly useful because of the general brilliant yellow-green fluorescence which is imparted to chromosomes when it is bound. An important technical advance in this area came from studies of Caspersson et al. (1968) who found that chromosome preparations treated with quinacrine mustard displayed high fluorescent intensity in localized regions. By this method, for example, the long arms of the human Y chromosome are rendered highly fluorescent and a Y-body can even be visualized in interphase nuclei (Pearson et al., 1970; Caspersson et al., 1970b). Because of the reactivity of mustards with the N-7 position of guanine, an affinity label model was proposed by Caspersson et al. (1968). It was postulated that quinacrine mustard specifically stained chromosome regions rich in GC base pairs, that the specificity resided in the side chain of quinacrine, and that...