title: Microfluidic leukocyte isolation for gene expression analysis in critically ill hospitalized patients.
abstract: BACKGROUND
  Microarray technology is becoming a powerful tool for diagnostic, therapeutic, and prognostic applications. There is at present no consensus regarding the optimal technique to isolate nucleic acids from blood leukocyte populations for subsequent expression analyses. Current collection and processing techniques pose significant challenges in the clinical setting. Here, we report the clinical validation of a novel microfluidic leukocyte nucleic acid isolation technique for gene expression analysis from critically ill, hospitalized patients that can be readily used on small volumes of blood.
  
  
  METHODS
  We processed whole blood from hospitalized patients after burn injury and severe blunt trauma according to the microfluidic and standard macroscale leukocyte isolation protocol. Side-by-side comparison of RNA quantity, quality, and genome-wide expression patterns was used to clinically validate the microfluidic technique.
  
  
  RESULTS
  When the microfluidic protocol was used for processing, sufficient amounts of total RNA were obtained for genome-wide expression analysis from 0.5 mL whole blood. We found that the leukocyte expression patterns from samples processed using the 2 protocols were concordant, and there was less variability introduced as a result of harvesting method than there existed between individuals.
  
  
  CONCLUSIONS
  The novel microfluidic approach achieves leukocyte isolation in <25 min, and the quality of nucleic acids and genome expression analysis is equivalent to or surpasses that obtained from macroscale approaches. Microfluidics can significantly improve the isolation of blood leukocytes for genomic analyses in the clinical setting.
authors: Surgical Services and Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School and Shriners Hospital for Children, Boston, MA, USA.
authors: Aman
authors: A
authors: Russom
authors: Palaniappan
authors: P
authors: Sethu
authors: Daniel
authors: D
authors: Irimia
authors: Michael N
authors: MN
authors: Mindrinos
authors: Steve E
authors: SE
authors: Calvano
authors: Iris
authors: I
authors: Garcia
authors: Celeste
authors: C
authors: Finnerty
authors: Cynthia
authors: C
authors: Tannahill
authors: Amer
authors: A
authors: Abouhamze
authors: Julie
authors: J
authors: Wilhelmy
authors: M Cecilia
authors: MC
authors: López
authors: Henry V
authors: HV
authors: Baker
authors: David N
authors: DN
authors: Herndon
authors: Stephen F
authors: SF
authors: Lowry
authors: Ronald V
authors: RV
authors: Maier
authors: Ronald W
authors: RW
authors: Davis
authors: Lyle L
authors: LL
authors: Moldawer
authors: Ronald G
authors: RG
authors: Tompkins
authors: Mehmet
authors: M
authors: Toner
mesh_terms: D002056:Burns / Q000473:pathology; D002469:Cell Separation; D016638:Critical Illness; D020869:Gene Expression Profiling; D006760:Hospitalization; D006801:Humans; D007962:Leukocytes / Q000737:chemistry / Q000166:cytology*; D046210:Microfluidic Analytical Techniques; D020411:Oligonucleotide Array Sequence Analysis; D012313:RNA / Q000302:isolation & purification; D014949:Wounds, Nonpenetrating / Q000473:pathology
chemical_list: D012313:RNA