title: Acquiring genome-wide gene expression profiles in Guthrie card blood spots using microarrays.
abstract: Standard Guthrie cards have been widely used to collect blood samples from essentially all USA and Japanese neonates for newborn screening programs. Thus, archival blood spot samples are a unique and comprehensive resource for molecular pathology studies. However, the challenge in using these samples is the presumed low quantity and degraded quality of nucleic acids that can be isolated from these samples, particularly the RNA. Here, we report a new assay using Agilent 4x44K microarrays for acquiring genome-wide gene expression profiles from blood spots on Guthrie cards. Due to the small amount of RNA obtained from each sample, major modifications, such as concentrating and amplifying the RNA and using a different labeling procedure, were performed. Approximately 9000 expressed genes can be detected after normalization of data, an increment of 260% in detection power compared with previously reported cDNA microarrays made in-house with standard procedures. The correlation coefficients in technical and biological replicates were 0.92 and 0.85, respectively, confirming the reproducibility of this study. This new and comprehensive assay will add value to the utility of archival Guthrie cards (e.g. neonatal blood spot cards) and open new opportunities to molecular epidemiology, pathology, genomic, and diagnostic studies of perinatal diseases.
authors.affiliation: Laboratory of Microarray Technology, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA.
authors.forename: Sok Kean
authors.initials: SK
authors.lastname: Khoo
authors.forename: Karl
authors.initials: K
authors.lastname: Dykema
authors.forename: Naga Manjari
authors.initials: NM
authors.lastname: Vadlapatla
authors.forename: David
authors.initials: D
authors.lastname: LaHaie
authors.forename: Saul
authors.initials: S
authors.lastname: Valle
authors.forename: David
authors.initials: D
authors.lastname: Satterthwaite
authors.forename: Sara Angeline
authors.initials: SA
authors.lastname: Ramirez
authors.forename: Janell Alee
authors.initials: JA
authors.lastname: Carruthers
authors.forename: Peterson Todd
authors.initials: PT
authors.lastname: Haak
authors.forename: James Howard
authors.initials: JH
authors.lastname: Resau
mesh_terms: D001800:Blood Specimen Collection / Q000379:methods*; 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