Electrophoretic Karyotyping of Yeasts

Electrophoretic karyotyping means the separation of intact chromosomal DNA according to its size on an agarose gel. Depending on the number and size of the chromosomes present in a strain, a specific banding pattern will be obtained. In order to reach this goal, two demands must be met. First, it is important to prepare the DNA without degradation by mechanical stress or by DNAses. Second, a method for the electrophoretic separation of the extremely large molecules must be developed. Conventional DNA electrophoresis is able to separate molecules of up to 50 kilobases. Yeast chromosomes range from several hundred to several thousand kilobases.