title: DNA banking: the effects of storage of blood and isolated DNA on the integrity of DNA.
abstract: Long-term storage of DNA is required for a number of genetic studies; prior to extraction, blood samples may be subject to elevated temperatures for variable intervals. We have studied the effect of temperatures ranging from -70 degrees C to +65 degrees C on human blood and on DNA extracted from it. DNA in solution stored at ambient temperatures up to 37 degrees C for 6 months was digestible by three different restriction endonucleases, whereas storage at 45 degrees C is deleterious after 6-7 weeks. DNA can be extracted from blood samples stored at -70 degrees C for at least 2 months or at 23 degrees C for a week or more, but blood stored at these temperatures may yield less high-molecular-weight DNA. Cell pellets from which plasma has been removed also can serve as a source of DNA. Isolated DNA stored dry for years (up to 30) is difficult to dissolve and may appear degraded, but a sample stored dry for 13 years and then in solution at -20 degrees C for 7 years appeared to be intact.
mesh_terms: D001793:Blood Preservation; D004247:DNA / Q000235:genetics / Q000302:isolation & purification*; D004249:DNA Damage; D004274:DNA, Recombinant; D006801:Humans; D007962:Leukocytes / Q000032:analysis; D012189:Retrospective Studies; D013696:Temperature; D014015:Tissue Banks
chemical_list: D004274:DNA, Recombinant; D004247:DNA