Preanalytical Procedures for DNA Studies: The Experience of the Interinstitutional Multidisciplinary BioBank (BioBIM)

Preanalytical variables, including the anticoagulants and stabilizing agents, time, storage temperature, and methods of DNA extraction applied to blood samples, may affect quality and quantity of isolated nucleic acids for future genomic applications. Considering the large number of collected samples, standard operating procedure optimization for whole blood preservation before DNA extraction is a crucial step in a biological repository. Moreover, the future application of the biological material may not be known subsequent to its extraction. To define standard operating procedures for whole blood preservation before DNA extraction, we aimed to determine whether different combinations of anticoagulants, blood storage temperatures, and time intervals before storage at -80°C might have an impact on quality and quantity of subsequent extracted DNA. After spectrophotometer quantification, the quality and integrity of DNA were assessed by agarose gel electrophoresis, polymerase chain reaction, and real-time polymerase chain reaction methods. We observed that decrease in DNA recovery during blood storage time was more pronounced at room temperature than at 4°C. Based on our experience, we recommend as anticoagulants of choice sodium citrate and ethylenediaminetetraacetate, whereas sodium citrate theophylline adenosine dipyridamole could represent an alternative choice, excluding a priori lithium heparin and Fluoride-Oxalate. Based on the overall evaluation criteria, we conclude that the procedures necessary to preserve the whole blood before the DNA extraction may have a significant impact on downstream molecular biological applications.