Kubota Y, Murashige S, Fujisaki Y
Nucleic Acids Symp Ser. 1986(17):219-22.
Absorption and fluorescence measurements of DNA-Hoechst 33258 complexes at high molar ratio of DNA phosphate to dye are consistent with the existence of two types of bound species. One type (Type I) predominates at high ionic strength, whereas the other (Type II) occurs at low ionic strength. The fluorescence peak (lambda fmax) depends on the excitation wavelength (lambda ex); lambda fmax shifts toward longer wavelength with increasing lambda ex. Optical properties obtained are summarized in the following: for Type I, lambda amax (absorption) = 352 nm, lambda fmax at lambda ex of 335 nm = 460 nm, tau (fluorescence lifetime) = 2.0-2.5 ns; for Type II, lambda amax = 360 nm, lambda fmax at lambda ex of 335 nm = 470 nm, tau = 4.0-5.0 ns. This behavior is interpreted in terms of solvent-solute relaxation. Type I corresponds to less hydrated bound species, while Type II to more hydrated bound species.
在DNA磷酸与染料的高摩尔比下，对DNA - 赫斯特33258复合物进行的吸收和荧光测量结果与两种结合物种的存在相一致。一种类型（I型）在高离子强度下占主导，而另一种（II型）出现在低离子强度下。荧光峰（λfmax）取决于激发波长（λex）；随着λex增加，λfmax向更长波长移动。所获得的光学性质总结如下：对于I型，λamax（吸收）= 352nm，在λex为335nm时λfmax = 460nm，τ（荧光寿命）= 2.0 - 2.5ns；对于II型，λamax = 360nm，在λex为335nm时λfmax = 470nm，τ = 4.0 - 5.0ns。这种行为是根据溶剂 - 溶质弛豫来解释的。I型对应水合程度较低的结合物种，而II型对应水合程度较高的结合物种。
