title: Gene expression and fiber type variations in repeated vastus lateralis biopsies.
abstract: BACKGROUND
  Muscle sample collection can introduce variation in any measured variable due to inter- and intramuscle variation. We investigated the variation in gene expression and fiber type composition after repeated biopsy sampling from the vastus lateralis muscle.
  
  
  METHODS
  Six subjects donated 3 tissue samples each. One hour after baseline sampling from 1 vastus lateralis muscle, samples from both vastus lateralis muscles were obtained.
  
  
  RESULTS
  The fiber type composition differed between biopsies taken from the same leg. There were no within-subject differences in gene expression between the 3 biopsies. Multivariate analysis supports a model in which gene expression differs significantly between individuals but is not affected by repeated muscle biopsy sampling from the same subject.
  
  
  CONCLUSIONS
  One vastus lateralis muscle sample per subject is sufficient to establish a reliable baseline for comparing gene expression representing selected pathways over time within the same individual.
authors.affiliation: Department of Community Medicine and Rehabilitation, Sports Medicine, Umeå University, Umå, Sweden.
authors.forename: Niklas
authors.initials: N
authors.lastname: Boman
authors.affiliation: Department of Public Health and Clinical Medicine, Medicine, Umeå University, Umeå, Sweden.
authors.forename: Jonas
authors.initials: J
authors.lastname: Burén
authors.affiliation: Department of Chemistry, Umeå University, Umeå, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Antti
authors.affiliation: Department of Community Medicine and Rehabilitation, Sports Medicine, Umeå University, Umå, Sweden.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Svensson
mesh_terms: D000328:Adult; D001706:Biopsy / Q000379:methods / Q000592:standards; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D052097:Quadriceps Muscle / Q000033:anatomy & histology* / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D055815:Young Adult
keywords: fiber type; gene expression; human; muscle; repeated sampling