Preparation of yeast RNA.

This unit provides two protocols for extraction of RNA from yeast that differ primarily in the method for lysing the yeast cells. The first protocol isolates RNA directly from intact yeast cells by extraction with hot acidic phenol. This yields RNA that is relatively free of contaminating DNA, is convenient to perform with multiple samples, and gives little or no sample-to-sample variation. In contrast, an alternate protocol relies upon disruption of cells by vigorous mixing with glass beads and denaturing agents. Although this procedure results in efficient breaking of the cells, the product is associated with residual DNA, and the procedure itself is troublesome when one is working with multiple samples. A second alternate protocol describes the scaling up of the first two procedures to isolate enough total RNA for poly (A)+ RNA preparation.