Scheid W
Can J Genet Cytol. 1979 Mar;21(1):145-9. doi: 10.1139/g79-019.
In 5-bromodeoxyuridine (BUdR)-substituted human chromsomes stained with 4'-6-diamidino-2-phenylindole (DAPI) differential staining is suppressed totally by the H+-donor cysteamine (concentration 0.08 M). We propose that differential staining appears because the double BUdR-substituted chromatid will be disintegrated via a photosensitive dye-visible light system. It is suggested that cysteamine prevents the production of strand breaks in DNA and, consequently, differential staining in BUdR-substituted chromosomes. Furthermore it is shown that differential staining with DAPI causes irreversible changes in the double BUdR-substituted chromatid. This finding can be explained with the above mentioned mechanism.
在用4′-6-二脒基-2-苯基吲哚(DAPI)染色的5-溴脱氧尿苷(BUdR)取代的人类染色体中,H⁺供体半胱胺(浓度0.08 M)完全抑制了差异染色。我们提出差异染色的出现是因为双BUdR取代的染色单体将通过光敏染料-可见光系统解体。有人认为半胱胺可防止DNA链断裂的产生,从而防止BUdR取代的染色体出现差异染色。此外,还表明用DAPI进行的差异染色会导致双BUdR取代的染色单体发生不可逆变化。这一发现可用上述机制来解释。