Detection of genomic DNA fragmentation during apoptosis (DNA ladder) and the simultaneous isolation of RNA from low cell numbers.

In the present paper we describe a rapid and sensitive method for the simultaneous isolation of total RNA and genomic plus low-molecular-weight DNA from apoptotic cells. Using this method, we were able to detect a DNA ladder from as low as 30,000 apoptotic cells in only 45 min including gel electrophoresis. In addition, RNA can be readily obtained from the same specimen to assess gene expression during apoptosis. This method therefore appears to be advantageous when sensitivity and low amounts of sample material are a limiting factor. Copyright 1999 Academic Press.