INCREASING THE DNA MELTING METHOD VALIDITY BY RE-ANALYSIS IMPLEMENTATION

The article explores the possibility of using repeated analyses based on the DNA melting method to increase their validity, namely, to reduce the error in determining the DNA melting temperature Tm. A statistically significant difference in the Tm values of the analyzed samples in successive analyses was experimentally revealed, which prevents the validity increase. It is shown that an increase in the temperature Tm on average by 0.12 deg. in the series of experiments is due to the evaporation of 1.65% of water from the test tube. A change in mass by 0.8 ± 0.1% of the total mass of water in test tubes was experimentally revealed as a result of a thermal regime similar to the analysis by the melting method, which partially confirms the assumption. It is recommended to take into account this effect during re-analyses using the DNA melting method and to implement measures that prevent water evaporation. Analytical expressions are given for the relative assessment of the sodium ion concentration changes and the water volume in the sample.