DNA extraction with organic solvents in gel barrier tubes

The authors describe the use of a special blood collection tube to isolate the offensive organic solvents. The customary use of these tubes (SST tube, Becton Dickinson, Rutherford, N.J.) is to separate serum from cells during centrifugation of blood. As blood samples are centrifuged in these collection tubes, the silica gel rises through the red cell layer and fixes itself between the red cells and serum. Similarly, they have found high molecular weight eukaryotic DNA (or plasmid preparations after alkaline lysis purification) can be safely separated from organic solvents after centrifugation.