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Series GSE19249 Query DataSets for GSE19249
Status Public on Nov 25, 2010
Title Quantitative Gene Expression Profiling in Formalin-Fixed Paraffin-Embedded Samples by Affymetrix Microarrays
Organism Homo sapiens
Experiment type Expression profiling by array
Summary Background: To date, few studies have systematically characterized microarray gene expression signal performance with degraded RNA from formalin-fixed paraffin-embedded (FFPE) specimens in comparison to intact RNA from unfixed fresh-frozen (FF) specimens.
Methodology: RNA was extracted and isolated from paired tumor and normal samples from both FFPE and FF kidney, lung and colon tissue specimens. Microarray signal dynamics on both the raw probe and probeset level were evaluated. A contrast metric was developed to directly compare microarray signal derived from RNA extracted from matched FFPE and FF specimens. Gene-level summaries were then compared to determine the degree of overlap in expression profiles.
Results: RNA extracted from FFPE material was more degraded and fragmented than FF, resulting in reduced dynamic range of expression signal. It was found that probe performance is not affected uniformly and declines sharply toward 5’ end of genes. The most significant differences in FFPE vs. FF signal were consistent across three tissue types and enriched with ribosomal genes.
Significance: Our results show that archived FFPE samples can be used to profile for expression signatures and assess differential expression similar to unfixed tissue sources. This study provides guidelines for application of these methods in the discovery, validation, and clinical application of microarray expression profiling with FFPE material.
 
Overall design 53 samples: 16 FF colon, 7 FFPE colon, 6 FF lung, 8 FFPE lung, 8 FF kidney, and 8 FFPE kidney specimens. Samples are paired tumor and normal tissue. 1-4 biological replicates.
 
Contributor(s) Abdueva D, Wing M, Schaub B, Triche T, Davicioni E
Citation(s) 20522636
Submission date Dec 01, 2009
Last update date Mar 25, 2019
Contact name Elai Davicioni
E-mail(s) elai.davicioni@veracyte.com
Organization name Veracyte, Inc
Street address 9725 Lusk Blvd
City San Diego
State/province California
ZIP/Postal code 92121
Country USA
 
Platforms (2)
GPL570 [HG-U133_Plus_2] Affymetrix Human Genome U133 Plus 2.0 Array
GPL571 [HG-U133A_2] Affymetrix Human Genome U133A 2.0 Array
Samples (53)
GSM477747 Colon FF A-1
GSM477748 Colon FF A-2
GSM477749 Colon FF A-3
Relations
BioProject PRJNA120789

Download family Format
SOFT formatted family file(s) SOFTHelp
MINiML formatted family file(s) MINiMLHelp
Series Matrix File(s) TXTHelp

Supplementary file Size Download File type/resource
GSE19249_RAW.tar 134.7 Mb (http)(custom) TAR (of CEL)
Processed data included within Sample table

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