Abstract
Cryopreservation of whole blood is useful for DNA collection, and clinical and basic research. Blood samples in ethylenediaminetetraacetic acid disodium salt (EDTA) tubes stored at − 80 °C are suitable for DNA extraction, but not for high-quality RNA extraction. Herein, a new methodology for high-quality RNA extraction from human blood samples is described. Quickly thawing frozen whole blood on aluminum blocks at room temperature could minimize RNA degradation, and improve RNA yield and quality compared with thawing the samples in a 37 °C water bath. Furthermore, the use of the NucleoSpin RNA kit increased RNA yield by fivefold compared with the PAXgene Blood RNA Kit. Thawing blood samples on aluminum blocks significantly increased the DNA yield by ~ 20% compared with thawing in a 37 °C water bath or on ice. Moreover, by thawing on aluminum blocks and using the NucleoSpin RNA and QIAamp DNA Blood kits, the extraction of RNA and DNA of sufficient quality and quantity was achieved from frozen EDTA whole blood samples that were stored for up to 8.5 years. Thus, extracting RNA from frozen whole blood in EDTA tubes after long-term storage is feasible. These findings may help advance gene expression analysis, as well as biomarker research for various diseases.
Highlights
Cryopreservation of whole blood is useful for DNA collection, and clinical and basic research
The RNA integrity numbers (RINs) of the samples from the P-Al and N-Al groups, which were thawed on an aluminum block at room temperature, were significantly higher than those of the samples from the P-37 and N-37 groups, which were thawed in a water bath at 37 °C (p = 0.044) (Fig. 2b)
RNA of high quantity and quality for expression analysis could be purified by appropriately thawing frozen whole blood samples and using the NucleoSpin RNA kit
Summary
Cryopreservation of whole blood is useful for DNA collection, and clinical and basic research. Extracting RNA from frozen whole blood in EDTA tubes after long-term storage is feasible These findings may help advance gene expression analysis, as well as biomarker research for various diseases. If blood is to be cryopreserved for RNA purification, it is recommended that peripheral leukocytes be removed before storage to eliminate RNase activity[5,6,7,8] and/or that blood be stored with RNA-stabilizing reagents, such as the PAXgene blood RNA tubes to prevent RNA d egradation[8,9,10,11] Without these precautions, it is difficult to extract intact RNA from cryopreserved whole blood samples in ethylenediaminetetraacetic acid disodium salt (EDTA) collection tubes. Increasing the amount of DNA to be extracted without compromising its quality would make it easier for institutions to provide samples
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call