title: Extraction of DNA from serum for high-throughput genotyping: findings from pilot studies within the Prostate Cancer Prevention Trial.
abstract: OBJECTIVE
  Deoxyribonucleic acid (DNA) extraction from blood and genotyping for candidate single nucleotide polymorphisms (SNP) is now an important part of almost all molecular epidemiologic studies. However, in many studies the amount of blood sample is limited or only serum is available. We conducted several pilot studies to identify methods for DNA extraction and high-throughput SNP genotyping of both white blood cell (WBC) and serum DNA that can be done centrally and reliably for large numbers of samples.
  
  
  METHODS
  We used biospecimens from the Prostate Cancer Prevention Trial (PCPT), a phase III, double-blind, placebo-controlled trial that tested the efficacy of finasteride for the primary prevention of prostate cancer. DNA was extracted from WBCs, from serum, and also from serum after organic solvent extraction for analysis of hormones. We also conducted blinded high-throughput genotyping in three laboratories to assess feasibility and reliability of results with differing methodologies using DNA from WBCs and from serum.
  
  
  RESULTS
  Genotyping of DNA extracted from WBCs resulted in highly reliable, reproducible results across laboratories using different genotyping platforms. However, genotyping with DNA extracted from serum did not provide reliable data using high-throughput multiplex approaches such as Sequenom (hME and iPLEX) and Applied Biosystems SNPlex, but was successful using Taqman.
  
  
  CONCLUSIONS
  Based on the results of these pilot studies, we conclude that DNA obtained from serum must be used judiciously, and that genotyping using multiplex methods is not suitable for serum DNA.
authors.affiliation: University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Ashraful
authors.initials: A
authors.lastname: Hoque
authors.forename: Phyllis
authors.initials: P
authors.lastname: Goodman
authors.forename: Christine B
authors.initials: CB
authors.lastname: Ambrosone
authors.forename: William D
authors.initials: WD
authors.lastname: Figg
authors.forename: Douglas K
authors.initials: DK
authors.lastname: Price
authors.forename: William
authors.initials: W
authors.lastname: Kopp
authors.forename: Xifeng
authors.initials: X
authors.lastname: Wu
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Conroy
authors.forename: Teresa A
authors.initials: TA
authors.lastname: Lehman
authors.forename: Regina M
authors.initials: RM
authors.lastname: Santella
mesh_terms: D019963:Clinical Chemistry Tests / Q000379:methods; D004273:DNA, Neoplasm / Q000032:analysis* / Q000097:blood; D005838:Genotype; D006801:Humans; D007962:Leukocytes / Q000737:chemistry*; D008297:Male; D010865:Pilot Projects; D011471:Prostatic Neoplasms / Q000097:blood / Q000235:genetics*
chemical_list: D004273:DNA, Neoplasm