Abstract
A new method for the determination of DNA concentration in solutions was developed. The method is based upon the principle that free methyl green in solution fades rapidly by addition of hydrogen peroxide, while methyl green bound to DNA does not fade. Therefore, the spectroscopic measurement of the rate of fading of a methyl green-DNA mixture gives us the concentration of free and bound dyes, from which the DNA concentration can be calculated. The new method has the advantage that the measurement can be conducted immediately after the preparation of the mixture, whereas several hours are required by other methods of using methyl green. The method was applied for the stoichiometric study of the binding of methyl green by native and heat-denatured DNA's, and the results were discussed, referring to the data previously reported for the interactions of DNA with various dyes such as aminoacridines and triphenylmethanes including methyl green.
