title: Pyrogen testing of lipid-based TPN using Mono Mac 6 monocyte cell line and DELFIA.
abstract: OBJECTIVE
  Measurement of lipopolysaccharide (LPS) induced interleukin-6 (IL-6) secretion in Mono Mac 6 cells.
  
  
  METHODS
  Dissociation-enhanced lanthanide fluoro immunoassay (DELFIA), a technique based on time-resolved fluorescence.
  
  
  RESULTS
  A comparison of DELFIA and the B9 bioassay showed a correlation between the results of the two assays. DELFIA did not show any crossreactivity with the human cytokines TNFalpha, IL-1beta, IL-1alpha, IL-2, IL-4, IFNgamma, murine IL-6 or LPS. In aqueous solution the detection limit was 2.5 pg LPS/ml, and in a 25% dilution of a lipid-based total parenteral nutrition (TPN) product it was 25 pg LPS/ml. TPN did not interfere with the DELFIA assay, but the IL-6 secretion from the Mono Mac 6 cells was inhibited at TPN concentrations above 25%.
  
  
  CONCLUSIONS
  A combination of Mono Mac 6 cells with DELFIA was found to be a reliable method for detecting LPS, but further validation by independent laboratories is justified.
authors.affiliation: The Royal Danish School of Pharmacy, Department of Biological Sciences, 2 LUniversitetsparken, 2100 Copenhagen, Denmark.
authors.forename: L
authors.initials: L
authors.lastname: Moesby
authors.forename: E W
authors.initials: EW
authors.lastname: Hansen
authors.forename: J D
authors.initials: JD
authors.lastname: Christensen
mesh_terms: D001681:Biological Assay; D002460:Cell Line; D003429:Cross Reactions; D004340:Drug Contamination; D005063:Europium; D015200:Fluoroimmunoassay / Q000379:methods; D006801:Humans; D007202:Indicators and Reagents; D015850:Interleukin-6 / Q000032:analysis; D008070:Lipopolysaccharides / Q000032:analysis*; D009000:Monocytes / Q000737:chemistry*; D010289:Parenteral Nutrition, Total; D011749:Pyrogens / Q000032:analysis*; D011786:Quality Control
chemical_list: D007202:Indicators and Reagents; D015850:Interleukin-6; D008070:Lipopolysaccharides; D011749:Pyrogens; D005063:Europium