title: Multiplex bead array assays for detection of soluble cytokines: comparisons of sensitivity and quantitative values among kits from multiple manufacturers.
abstract: BACKGROUND
  Multiplex bead array assays permit simultaneous cytometric quantitation of multiple cytokines in solution by capturing these to spectrally distinct beads. Because several manufacturers offer reagents to quantitate the same cytokines on a single instrument, a comparison should be made to determine whether these kits yield similar data and whether these data are comparable to enzyme-linked immunosorbent assay (ELISA).
  
  
  METHODS
  This study compared cytokine detection kits by using Luminex 100. Twenty-six serum samples from seven subjects were analyzed for interferon-gamma, interleukins 1beta, 6, and 8, and tumor necrosis factor-alpha by using multiplex kits from LINCO Research, Bio-Rad Laboratories, R&D Systems, and BioSource International. Each assay was performed according to the manufacturers' specifications. Standard curves were generated by using reference concentrations supplied by each manufacturer. ELISAs for interleukin-8 were performed by using kits from R&D and BioSource.
  
  
  RESULTS
  Cytokine levels followed similar patterns, although absolute concentrations differed among kits. ELISA and Luminex values for interleukin-8 were similar in kits from the same manufacturer.
  
  
  CONCLUSIONS
  Because relative cytokine measurements are often valuable when performed serially, it may be possible to make interlaboratory comparisons by using different kits. When comparison of absolute values is crucial, kits from the same supplier should be used. Within-vendor, bead array, and ELISA values appear comparable.
authors.affiliation: Warren G. Magnuson Clinical Center, Critical Care Medicine Department, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Sameena S
authors.initials: SS
authors.lastname: Khan
authors.forename: Meghan S
authors.initials: MS
authors.lastname: Smith
authors.forename: Debra
authors.initials: D
authors.lastname: Reda
authors.forename: Anthony F
authors.initials: AF
authors.lastname: Suffredini
authors.forename: J Philip
authors.initials: JP
authors.lastname: McCoy
mesh_terms: D016207:Cytokines / Q000096:biosynthesis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D007249:Inflammation; D007371:Interferon-gamma / Q000097:blood; D007375:Interleukin-1 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D016209:Interleukin-8 / Q000097:blood / Q000378:metabolism; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D016207:Cytokines; D007375:Interleukin-1; D015850:Interleukin-6; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma