The Integrity and Yield of Genomic DNA Isolated from Whole Blood Following Long-Term Storage at -30°C

Biopreserv Biobank. 2018 Apr;16(2):106-113. doi: 10.1089/bio.2017.0050. Epub 2018 Jan 3.

Abstract

Long-term storage of whole blood can affect the integrity of DNA if it is not done under optimal conditions. The aim of this study was to determine whether long-term storage (2-19 years) of whole blood samples at -30°C had a negative effect on the quality or quantity of genomic DNA that could be recovered at extraction. Genomic DNA was isolated from 2758 whole blood samples collected in 4 mL EDTA vacutainers from 1997 to 2012. DNA was extracted using the Qiagen® FlexiGene® DNA kit. The average storage duration at -30°C was 12 years. The quality and quantity of the isolated DNA were assessed using spectrophotometry (NanoDrop™), a fluorometric assay for double-stranded DNA (Qubit™), and agarose gel electrophoresis. The mean DNA yield per sample was found to be 114 μg from whole blood volumes that ranged from 0.5 to 4 mL. The mean A260/280 ratio and median A260/280 ratios were both 1.8. No correlation was found between the duration of storage and the total yield or the quality of DNA extracted. These data suggest that high-quality DNA can be extracted from whole blood samples that are stored at -30°C for up to 19 years.

Keywords: DNA quality; DNA storage; long-term storage.

MeSH terms

  • Blood Preservation*
  • Blood*
  • Cryopreservation*
  • DNA / chemistry
  • DNA / isolation & purification*
  • Genome, Human*
  • Humans
  • Time Factors

Substances

  • DNA