title: Archived unfrozen neonatal blood spots are amenable to quantitative gene expression analysis.
abstract: BACKGROUND
  State laws in the USA mandate that blood be drawn from all newborn infants to screen for health-threatening conditions. These screening assays consume only a small portion of the blood samples, which are collected on filter paper ('Guthrie') cards. Many states archive unused blood spots, often in unrefrigerated storage.
  
  
  OBJECTIVE
  While individual RNA transcripts have been identified from archived neonatal blood spots, no study to date has performed quantitative analysis of archived blood spot RNA.
  
  
  METHODS
  We demonstrate that RNA can be isolated and amplified from newborn blood spots stored unfrozen for as long as 9 years, and can be analyzed by microarray and qPCR.
  
  
  RESULTS
  Microarray assays of archived neonatal blood spots consistently detected 3,000-4,000 expressed genes with correlations of 0.90 between replicates. Blood spot mRNA is amenable to qPCR and we detected biologically relevant expression levels of housekeeping and immune-mediating genes.
  
  
  CONCLUSIONS
  These experiments demonstrate the feasibility of using blood spots as a source of RNA which can be analyzed using quantitative microarray and qPCR assays. The application of these methods to the analysis of widely collected biological specimens may be a valuable resource for the study of perinatal determinants of disease development.
authors.affiliation: Laboratory of Microarray Technology, Van Andel Research Institute, Grand Rapids, Mich. 49503, USA.
authors.forename: Peterson T
authors.initials: PT
authors.lastname: Haak
authors.forename: Julia V
authors.initials: JV
authors.lastname: Busik
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Kort
authors.forename: Maria
authors.initials: M
authors.lastname: Tikhonenko
authors.forename: Nigel
authors.initials: N
authors.lastname: Paneth
authors.forename: James H
authors.initials: JH
authors.lastname: Resau
mesh_terms: D001800:Blood Specimen Collection; D020869:Gene Expression Profiling / Q000379:methods*; D006801:Humans; D007231:Infant, Newborn; D015997:Neonatal Screening / Q000379:methods*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000097:blood*; D013997:Time Factors
chemical_list: D012333:RNA, Messenger
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