Method for Simultaneous RNA and DNA Isolation from Biopsy Material, Culture Cells, Plants and Bacteria

摘要

The analysis of RNA and DNA in clinical biopsy material for diagnostic and research purposes has become more and more important. Currently available methods and kits are used to focus on the extraction of only one kind of nucleic acid, but since the amount of biopsy material is often limited, a method for the simultaneous isolation of both kinds of nucleic acids from one sample is desirable. In contrast to DNA, RNA is rapidly degraded, and biopsy material often cannot be immediately preserved duringthe surgery process. We found that it is necessary to totally break up the tissue to get RNA from the inner parts of the biopsy where RNA degradation has not yet occurred, as physiologic conditions have been retained in this region for a longer time. Some tissues, especially skin, are very difficult to break up, and conventional methods (e.g., guanidine thio-cyanate) (2) yield too little intact RNA (20-30 ng/mg tissue) of total RNA with an average size of 0.2-0.4 kb because of degradation, or the DNA is fragmented into small pieces because of harsh grinding procedures. For these reasons, we developed this method, which allows us to isolate simultaneously high-molecular-weight DNA and RNA in sufficient amounts from fresh and cryo-preserved material.