title: Quantitative analysis of genomic DNA degradation in whole blood under various storage conditions for molecular diagnostic testing.
abstract: Proper storage of whole blood is crucial for isolating nucleic acids from leukocytes and to ensure adequate performance of downstream assays in the molecular diagnostic laboratory. Short-term and long-term storage recommendations are lacking for successful isolation of genomic DNA (gDNA). Container type (EDTA or heparin), temperature (4 °C and room temperature) and time (1-130 days) were assessed as criterion for sample acceptance policies. The percentage of integrated area (%Ti) between 150 and 10,000 bp from the 2200 TapeStation electropherogram was calculated to measure gDNA degradation. Refrigerated EDTA samples yielded gDNA with low %Ti (high quality). Heparinized samples stored at room temperature yielded gDNA of worst quality. Downstream analysis demonstrated that the quality of the gDNA correlated with the quality of the data; samples with high %Ti generated significantly lower levels of high molecular weight amplicons. Recommendations from these analyses include storing blood samples intended for nucleic acid isolation in EDTA tubes at 4 °C for long term storage (>10 days). gDNA should be extracted within 3 days when blood is stored at room temperature regardless of the container. Finally, refrigerated heparinized samples should not be stored longer than 9 days if expecting high quality gDNA isolates. Laboratories should consider many factors, in addition to the results obtained herein, to update their policies for sample acceptance for gDNA extraction intended for molecular genetic testing.
authors.affiliation: Department of Molecular Genetic Pathology, Arkansas Children's Hospital, 1 Children's Way, Little Rock, AR 72212, USA.
authors.forename: Jessalyn
authors.initials: J
authors.lastname: Permenter
authors.affiliation: Department of Molecular Genetic Pathology, Arkansas Children's Hospital, 1 Children's Way, Little Rock, AR 72212, USA.
authors.forename: Arjun
authors.initials: A
authors.lastname: Ishwar
authors.affiliation: Department of Molecular Genetic Pathology, Arkansas Children's Hospital, 1 Children's Way, Little Rock, AR 72212, USA.
authors.forename: Angie
authors.initials: A
authors.lastname: Rounsavall
authors.affiliation: Department of Molecular Genetic Pathology, Arkansas Children's Hospital, 1 Children's Way, Little Rock, AR 72212, USA.
authors.forename: Maddie
authors.initials: M
authors.lastname: Smith
authors.affiliation: Department of Molecular Genetic Pathology, Arkansas Children's Hospital, 1 Children's Way, Little Rock, AR 72212, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Faske
authors.affiliation: Department of Molecular Genetic Pathology, Arkansas Children's Hospital, 1 Children's Way, Little Rock, AR 72212, USA; University of Arkansas for Medical Sciences, Little Rock, AR 72212, USA.
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Sailey
authors.affiliation: Department of Molecular Genetic Pathology, Arkansas Children's Hospital, 1 Children's Way, Little Rock, AR 72212, USA; University of Arkansas for Medical Sciences, Little Rock, AR 72212, USA. Electronic address: alfarom@archildrens.org.
authors.forename: Maria P
authors.initials: MP
authors.lastname: Alfaro
mesh_terms: D001800:Blood Specimen Collection / Q000379:methods*; D004247:DNA / Q000032:analysis* / Q000097:blood* / Q000302:isolation & purification; D053938:DNA Fragmentation; D004492:Edetic Acid / Q000378:metabolism; D015894:Genome, Human; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000379:methods; D011309:Preservation, Biological / Q000379:methods*; D013696:Temperature; D013997:Time Factors
chemical_list: D004247:DNA; D004492:Edetic Acid
keywords: Clinical lab; Diagnostic testing; Extraction; Genomic DNA; Guidelines; Sample storage