COMPARATIVE-STUDY OF DIFFERENT METHODS OF DETERMINING TM OF BACTERIAL DNA

Abstract

Melting point curves of DNA are used to calculate average GC content. Four methods of Tm [melting point] determination are described and are used in the case of all DNA samples studied. The results presented confirm that thermal denaturation curves are asymetrical and this limits the use of normal probability paper and regression lines methods. Best reproductibility is obtained by a study of the function .DELTA.DO/.DELTA.t = f(t), followed by a linear interpolation of the median. This approach yields at the same time interesting information about bacterial DNA. The graphic determination of Tm appears to be the method for choice for routine analysis. [This study relates to bacterial taxonomy.].