Bonaly J, Bre M H, Lefort-Tran M, Mestre J C
Cytometry. 1987 Jan;8(1):42-5. doi: 10.1002/cyto.990080107.
DNA stainability by different fluorochromes has been compared in exponentially dividing and stationary Euglena cells. With the intercalating fluorochromes, ethidium bromide, acridine orange and DAPI, a decrease of fluorescence intensity of the G1 cells is observed when cells enter stationary stage. However this decrease of fluorescence is not obtained with the nonintercalating fluorochrome Hoechst 33258. If nuclear basic proteins are extracted, however, the intensity of staining by either Hoechst 33258 or ethidium-bromide is comparable in stationary and dividing cells. Therefore, the decrease of fluorescence intensity of the G1 cells observed during the transition from exponential to stationary phase is not due to a loss of DNA but is related to the exposure of chromatin binding sites for ethidium bromide. In Euglena cells, DNA accessibility for intercalating fluorochromes depends upon chromatin structure and consequently upon cell age.
已对指数生长期和静止期的眼虫细胞中不同荧光染料对DNA的染色性进行了比较。对于嵌入型荧光染料溴化乙锭、吖啶橙和4',6-二脒基-2-苯基吲哚（DAPI），当细胞进入静止期时，观察到G1期细胞的荧光强度降低。然而，对于非嵌入型荧光染料Hoechst 33258，并未观察到这种荧光降低现象。但是，如果提取核碱性蛋白，那么在静止期和分裂期细胞中，Hoechst 33258或溴化乙锭的染色强度相当。因此，在从指数生长期向静止期转变过程中观察到的G1期细胞荧光强度降低并非由于DNA损失，而是与溴化乙锭的染色质结合位点暴露有关。在眼虫细胞中，嵌入型荧光染料对DNA的可及性取决于染色质结构，因而取决于细胞年龄。
