title: Comparison of blood RNA isolation methods from samples stabilized in Tempus tubes and stored at a large human biobank.
abstract: BACKGROUND
  More than 50,000 adult and cord blood samples were collected in Tempus tubes and stored at the Norwegian Institute of Public Health Biobank for future use. In this study, we systematically evaluated and compared five blood-RNA isolation protocols: three blood-RNA isolation protocols optimized for simultaneous isolation of all blood-RNA species (MagMAX RNA Isolation Kit, both manual and semi-automated protocols; and Norgen Preserved Blood RNA kit I); and two protocols optimized for large RNAs only (Tempus Spin RNA, and Tempus 6-port isolation kit). We estimated the following parameters: RNA quality, RNA yield, processing time, cost per sample, and RNA transcript stability of six selected mRNAs and 13 miRNAs using real-time qPCR.
  
  
  RESULTS
  Whole blood samples from adults (n = 59 tubes) and umbilical cord blood (n = 18 tubes) samples collected in Tempus tubes were analyzed. High-quality blood-RNAs with average RIN-values above seven were extracted using all five RNA isolation protocols. The transcript levels of the six selected genes showed minimal variation between the five protocols. Unexplained differences within the transcript levels of the 13 miRNA were observed; however, the 13 miRNAs had similar expression direction and they were within the same order of magnitude. Some differences in the RNA processing time and cost were noted.
  
  
  CONCLUSIONS
  Sufficient amounts of high-quality RNA were obtained using all five protocols, and the Tempus blood RNA system therefore seems not to be dependent on one specific RNA isolation method.
authors: Norwegian Institute of Public Health, P.O Box 4404, 0403, Nydalen, Oslo, Norway.
authors: Jeanette
authors: J
authors: Aarem
authors: Norwegian Institute of Public Health, P.O Box 4404, 0403, Nydalen, Oslo, Norway.
authors: Gunnar
authors: G
authors: Brunborg
authors: Norwegian Institute of Public Health, P.O Box 4404, 0403, Nydalen, Oslo, Norway.
authors: Kaja K
authors: KK
authors: Aas
authors: Norwegian Institute of Public Health, P.O Box 4404, 0403, Nydalen, Oslo, Norway.|Institute for Energy Technology, Kjeller, Norway.
authors: Kari
authors: K
authors: Harbak
authors: Norwegian Institute of Public Health, P.O Box 4404, 0403, Nydalen, Oslo, Norway.
authors: Miia M
authors: MM
authors: Taipale
authors: Norwegian Institute of Public Health, P.O Box 4404, 0403, Nydalen, Oslo, Norway.
authors: Per
authors: P
authors: Magnus
authors: Norwegian Institute of Public Health, P.O Box 4404, 0403, Nydalen, Oslo, Norway.
authors: Gun Peggy
authors: GP
authors: Knudsen
authors: Norwegian Institute of Public Health, P.O Box 4404, 0403, Nydalen, Oslo, Norway. nur.duale@fhi.no.
authors: Nur
authors: N
authors: Duale
mesh_terms: D000328:Adult; D018070:Biological Specimen Banks; D001793:Blood Preservation / Q000379:methods*; D005312:Fetal Blood / Q000378:metabolism; D006801:Humans; D035683:MicroRNAs / Q000097:blood; D012313:RNA / Q000097:blood* / Q000302:isolation & purification*; D020871:RNA Stability; D012333:RNA, Messenger / Q000097:blood
chemical_list: D035683:MicroRNAs; D012333:RNA, Messenger; D012313:RNA
keywords: Biobank; Cord blood; Epigenetics; Gene expression; MiRNA; MoBa; Noncoding RNA; RNA isolation; Tempus tubes; The Norwegian Mother and Child Cohort Study