Bloom S E, Hsu T C
Chromosoma. 1975 Jul 21;51(3):261-7. doi: 10.1007/BF00284819.
Differential fluorescence of sister chromatids (SCD) and sister chromatid exchanges (SCE) were visualized in chromosomes obtained directly from growing chicken embryos. SCD was obtained by exposing 3-day embryos to BrdU (12.5-50 mug) in ovo for 26 hours and staining air dried chromosome preparations with 33258 Hoechst. Bright, stable fluorescence and continued SCD were achieved if slides were mounted in McIlvaine's pH 4.4 buffer. Embryo growth, mitotic activity and gross chromosome morphology were not adversely altered by the BrdU treatments. The SCE rate was estimated to be 0.07 SCEs per macrochromosome and 0.75 SCEs per metaphase for two cell cycles.
在直接从生长中的鸡胚获取的染色体中观察到了姐妹染色单体差异荧光（SCD）和姐妹染色单体交换（SCE）。通过在卵内将3日龄胚胎暴露于BrdU（12.5 - 50微克）26小时，并使用33258 Hoechst对空气干燥的染色体标本进行染色来获得SCD。如果将载玻片安装在pH 4.4的麦氏缓冲液中，则可实现明亮、稳定的荧光以及持续的SCD。BrdU处理并未对胚胎生长、有丝分裂活性和总体染色体形态产生不利影响。在两个细胞周期中，估计每个大染色体的SCE率为0.07次SCE，每个中期的SCE率为0.75次SCE。
