藏红T在核酸分子表面进行长距组装的光谱特征

表征了藏红Ｔ（ＳＴ）在核酸分子表面进行长距组装的共振光散射光谱、电子吸收和发射特征。结果表明，ｐＨ７．０５、离子强度０．００４５下ＳＴ在核酸表面进行的长距组装随着ＳＴ与核酸的摩尔比（Ｒ）不同涉及到两种作用机理，当Ｒ〉１．３时，长距组装表现为紫移的减色效应和荧注猝灭，在３２８．０ｎｍ、４７２．０ｎｍ和５７２。０ｎｍ；Ｒ〈１．３３时，长距组装产物发生离解，具有红移的减色效应、荧光猝灭和微弱的共振光散射

Spectral characteristics of the long range assembly of safranine T on the molecular surfaces of nucleic acids

The long\|range assembly of Safranine T(ST) on the molecular surfaces of nucleic acids is characterized by measuring resonance light scattering (RLS), electronic absorption and fluorescence emission. It was found that the long range assembly of ST on the molecular surfaces of nucleic acids at pH 7.05 and ionic strength 0.004 5, depending on the molar ratio of ST to nucleic acids, involves two processes. When the molar ratio of ST to nucleic acids is larger than 1.33, the long range assembly of ST on the molecular surface of nucleic acids occurs, which characterizes hypsochromicly hypochromic effect, fluorescence quenching, and three strong enhanced peaks of resonance light\|scattering at 328.0, 472.0 and 572.0 nm. When the molar ratio is lower than 1.33, however, the disassociation of the species of the long range assembly of ST takes places, which characterizes bathochromically hypochromic effect, fluorescence quenching, and weak enhanced resonance light-scattering. Intercalative binding of ST in to DNA takes place in the process of the disassociation of the assembly species.