Simultaneous RNA and DNA Extraction from Biopsy Material, Culture Cells, Plants, and Bacteria

The analysis of RNA and
DNA
from clinical biopsy material for diagnostic and research purposes has become more and more important. Currently, available methods and kits are focusing on the extraction of only one kind of nucleic acid, but, as 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 in the biopsy material which often cannot be immediately conserved during the extraction. It was found that it is necessary to break up the tissue totally to get RNA from the inner parts of the biopsy where RNA degradation has not yet proceeded so far, as body like 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 thiocyanate), (
1
) yield too little and strongly degraded RNA (20–30 ng/mg tissue) of total RNA with an average size of 0.2–0.4 kb).