title: Multiple cytokine analysis in human tears: an optimized procedure for cytometric bead-based assay.
abstract: OBJECTIVE
  To compare instruments and reagents used for cytometric bead-based assay (CBA) of cytokines in human tears.
  
  
  METHODS
  Two CBA instruments and reagent kits from five vendors were compared in parallel. Vendor protocols were modified to accommodate tear volumes. Precision, recovery, dilution linearity, and stability were evaluated.
  
  
  RESULTS
  Luminextrade mark and Bio-Radtrade mark proved optimal for tear CBA. Good correlation for dilution linearity was observed (r > 0.80, p < 0.05) for 1-4-mu l sample volumes. Samples were stable for 30 min at 25 degrees C.
  
  
  CONCLUSIONS
  Many tear cytokines can be reliably measured by CBA using an optimized protocol. Concentrations remain stable during periods consistent with collection.
authors.affiliation: School of Optometry, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Martin W
authors.initials: MW
authors.lastname: LaFrance
authors.forename: Lucy E
authors.initials: LE
authors.lastname: Kehinde
authors.forename: Roderick J
authors.initials: RJ
authors.lastname: Fullard
mesh_terms: D000328:Adult; D016207:Cytokines / Q000032:analysis*; D005136:Eye Proteins / Q000032:analysis*; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D013048:Specimen Handling; D013666:Tears / Q000737:chemistry*
chemical_list: D016207:Cytokines; D005136:Eye Proteins; D011933:Reagent Kits, Diagnostic; C042434:tear proteins