Silver and mercury ions are known to react with the bases of nucleic acids in solution. At low cation/base ratios Ag+ has an affinity for GC pairs in DNA, whereas Hg++ is preferentially bound to AT-rich nucleic acids. We have used fluorometry to measure the effect of these cations on the fluorescenc
Molecular basis of chromosome banding
โ Scribed by K. Simola; R.-K. Selander; A. Chapelle; G. Corneo; E. Ginelli
- Publisher
- Springer
- Year
- 1975
- Tongue
- English
- Weight
- 447 KB
- Volume
- 51
- Category
- Article
- ISSN
- 0009-5915
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โฆ Synopsis
The effects of mouse satellite, main band and total DNA on the fluorescence intensity of quinacrine and of the bibenzimidazole derivative Hoechst 33258 were tested in solution. No significant differences were noticed between the double-stranded DNAs in spite of the 5% difference in AT-content between satellite and main band DNA. Single-stranded DNAs enhanced the fluorescence intensity of Hoechst 33258 far less than double-stranded DNAs. Having been denaturated and then reassociated the DNA fractions were intermediate in their enhancing effects on the fluorescence intensity of Hoechst 33258, the differences presumably being due to different degrees of reassociation. The effect of denatured and subsequently reassociated satellite DNA on the fluorescence intensity of quinacrine was similar to that of the native DNAs. Main band and total DNA quenched the fluorescence intensity of quinacrine more after denaturation-reassociation than it did when native. In the discussion the results are related to known cytological data.
๐ SIMILAR VOLUMES
The interaction of Hoechst 33258 with DNA has been examined to help clarify the mechanisms of banding. 1. In agreement with previous studies Hoechst fluorescence is enhanced to a greater degree in AT-rich compared to GC-rich DNA. 2. Hoechst causes an increase in the DNA Tm which is greater at the hi
The binding of methylene blue to DNA and chromatin treated in various ways was examined by equilibrium dialysis. The maximum r value (moles of bound dye/mole of nucleotide) was 1.0 for DNA, 0.6 for unfixed chromatin, and 0.83 for chromatin fixed in methanol-acetic acid. When fixed chromatin was trea
Prior studies on subfractions of mouse and Kangaroo rat DNA have suggested that variations in base concentration within a given genome may not be great enough to account for Q-banding. To examine this with another species, calf DNA was subfractionated by CsCl ultracentrifugation into GC-rich satelli