title: [Detection of endotoxin activity in water environment and analysis of influence factors for TAL assay].
abstract: Endotoxins, derived from cell walls of most Gram-negative bacteria and some cyanobacteria, are common pyrogen and highly immunogenic molecules, and related to many diseases. In this paper, a detection method for endotoxin activity in water environment using kinetic-turbid assay of Tachypleus Amebocyte Lysate (TAL) was established, the influence of pH and salts on TAL assay was investigated. Results showed that it was favorable for TAL assay in the pH range of 6.0-8.4, at low pHs, inhibition results were observed and opposite results were obtained at high pHs. The pH should be adjusted by Tris-HCl (pH = 7.4) buffer before the endotoxin detection. No significant interference was shown in the detection of water containing NaCl, Na2SO4, CaCl2, MgCl2 and KCl with a concentration of less than 50 mg x L(-1), however, the inhibition occurred at the concentration up to 1000-10,000 mg x L(-1). Only 2. 5 mg x L(-1) of FeCl, Fe2(SO4)3, AlCl3 and Al2 (SO4)3 caused significant inhibition. Endotoxin activities of ultrapure water, tap water and recreational water were detected by TAL assay, and their endotoxin activities were < 0.06 EU x mL(-1), 0.46 EU x mL(-1) and 432. 68 EU x mL(-1), respectively.
authors.affiliation: School of Environment, Tsinghua University, Beijing 100084, China. zhangcancqu@163.com
authors.forename: Can
authors.initials: C
authors.lastname: Zhang
authors.forename: Wen-jun
authors.initials: WJ
authors.lastname: Liu
authors.forename: Ming-lu
authors.initials: ML
authors.lastname: Zhang
authors.forename: Fang
authors.initials: F
authors.lastname: Tian
authors.forename: Wen
authors.initials: W
authors.lastname: Sun
authors.forename: Ling-jia
authors.initials: LJ
authors.lastname: Qian
authors.forename: Rui
authors.initials: R
authors.lastname: Zhan
mesh_terms: D000818:Animals; D004731:Endotoxins / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D006737:Horseshoe Crabs; D008033:Limulus Test / Q000379:methods*; D008565:Membrane Proteins / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D004731:Endotoxins; D008565:Membrane Proteins; C025357:endotoxin binding proteins; D014867:Water