- Collection:
- Atlanta University and Clark Atlanta University Theses and Dissertations
- Title:
- Fourier transform infrared spectroscopic study of intercalation of ethidium bromide in calf thymus DNA and poly(da dt), 1992
- Creator:
- Gates, Reba A.
- Date of Original:
- 1992-12-01
- Subject:
- Degrees, Academic
Dissertations, Academic - Location:
- United States, Georgia, Fulton County, Atlanta, 33.749, -84.38798
- Medium:
- theses
- Type:
- Text
- Format:
- application/pdf
- Description:
- An 8 mole (base pair)/liter aqueous solution of DNA, and a 4 mmole (base pair) aqueous solution of Poly(dA dT) were prepared for the study of the physical mechanism of complexation with an ethidium bromide solution. A 4 mmole ethidium bromide solution was added to a 1 mL DNA solution in lOO/uL increments and was analyzed via Fourier Transform Infrared (FT IR) Spectroscopy. An infrared spectrum of the mixture after each incremental addition was obtained. The ratios of the ethidium bromide to DNA base pairs for the resulting solutions were as follows: 1/20, 1/10, 1/6.7, 1/5, 1/3.3, 1/2.9, 1/2.5, 1/2.2, and 1/2. The resulting infrared spectra of these solutions indicated that the interaction of ethidium bromide with DNA in aqueous media exhibits two different modes at different relative concentrations of DNA and ethidium bromide. The first type of interaction which is most prominent for the lower ratio mixtures (< 1/5) is intercalation. This interaction is characterized by a shift (Acm1) in the phosphate bands of DNA. The second type of interaction is groove binding of the ethidium bromide to DNA which is indicated by the growth of a new feature at 1260 wavenumber (cm1). A 2 mmole ethidium bromide solution was utilized for the preparation of Poly(dA dT)/ethidium bromide solutions resulting in solutions with the same ratios of ethidium bromide to Poly(dA dT) as those for the ethidium to DNA solutions. The spectra of the Poly(dA dT) solutions showed the shifting of the phosphate infrared bands just as the DNA complexes, but there was distinct splitting of the 1214 cm'1 band and the 1050 cm1. This splitting is due to the two different phosphate environments and phosphodiester environments of dA and dT.
- External Identifiers:
- Metadata URL:
- http://hdl.handle.net/20.500.12322/cau.td:1992_gates_reba_a
- Rights Holder:
- Clark Atlanta University
- Holding Institution:
- Atlanta University Center Robert W. Woodruff Library
- Rights:
-
