A convenient method of DNA extraction from blood anticoagulated with EDTA.

Surplus blood often remains after routine clinical tests using EDTA-anticoagulated samples. To use this blood for DNA analysis, we isolated white cells by adherence to polyethylene terephthalate fibers, which could be stored for several weeks transported by mail after methanol fixation. DNA yield was sufficient and correlated with white cell count. Extracted DNA was free of hemoglobin contamination and durable to polymerase chain reaction and enzyme digestion, which yielded products visualized as well-separated bands on electrophoresis. We found our method to be practical for the routine clinical laboratory.