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Home List of Titles The use of second derivative plots for the determination of mol% guanine plus cytosine of DNA by the thermal denaturation method
Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/232333
- The use of second derivative plots for the determination of mol% guanine plus cytosine of DNA by the thermal denaturation method
- Sly, L. I.; Blackall, Linda L.; Kraat, P. C.; Tian-Shen, Tao; Sangkhobol, Vullapa
- Procedures for the estimation of thermaldenaturation temperatures for the determination of the mol percent G+C base composition of bacterial DNA have been examined with a view to simplifying the procedure and taking advantage of developments in microprocessor controlled spectrophotometers. Thermaldenaturation profiles of DNA from 40 strains with base compositions ranging from 35 to 70 mol percent G+C were studied. Thermaldenaturation temperatures were determined by the conventional Tmmethod and by using secondderivativeplots to determine the temperature of inflection (Ti). The results showed that there is a close linear correlation between mol percent G+C values calculated using Tm or Ti as the thermaldenaturation temperature, provided the thermaldenaturation temperature of the internal reference DNA is estimated in the same way. Actual Ti values were approximately 0.3 degrees Celcius higher than corresponding Tm values but the increase was consistent across the range of DNA samples studied. The results also showed that the error introduced by disregarding correction for the effect of thermal expansion was not consistent across the range of DNA samples studied. However, the error was small and in practical terms could be neglected.
- Publication type
- Journal article
- Journal of Microbiological Methods, Vol. 5, no. 3-4 (Aug 1986), pp. 139-156
- Publication year
- FOR Code(s)
- 0605 Microbiology; 1108 Medical Microbiology
- Bacterium; DNA; DNA base composition; Melting point; Methodology; Nonhuman
- Publisher URL
- Copyright © 1986 Published by Elsevier B.V.
- Peer reviewed