title: Studies on purification of methamidophos monoclonal antibodies and comparative immunoactivity of purified antibodies.
abstract: OBJECTIVE
  To purify Methamidophos (Met) monoclonal antibodies with two methods and compare immune activity of purified antibodies.
  
  
  METHODS
  Caprylic acid ammonium sulphate precipition (CAASP) method and Sepharose protein-A (SPA) affinity chromatography method were used to purify Met monoclonal antibodies, UV spectrum scanning was used to determine protein content and recovery of purified antibodies, sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE) was used to analyze the purity of purified antibodies, and enzyme-linked immunosorbent assay (ELISA) was used to determine immune activity of purified antibodies.
  
  
  RESULTS
  Antibody protein content and recovery rate with CAASP method were 7.62 mg/mL and 8.05% respectively, antibody protein content and recovery rate with SPA method were 6.45 mg/mL and 5.52% respectively. Purity of antibodies purified by SPA method was higher than that by CAASP method. The half-maximal inhibition concentration (IC50) of antibodies purified by SPA to Met was 181.26 microg/mL, and the linear working range and the limit of quantification (LOD) were 2.43-3896.01 microg/mL and 1.03 microg/mL, respectively. The IC50 of antibodies purified by CAASP to Met was 352.82 microg/mL, and the linear working range and LOD were 10.91-11412.29 microg/mL and 3.42 microg/mL, respectively.
  
  
  CONCLUSIONS
  Antibodies purified by SPA method are better than those by CAASP method, and Met monoclonal antibodies purified by SPA method can be used to prepare gold-labelled testing paper for analyzing Met residue in vegetable and drink water.
authors.affiliation: Zhongshan Medical School, Sun Yat-Sen (Zhongshan) University, Guangzhou 510089, China. suqingz@hotmail.com
authors.forename: Su-Qing
authors.initials: SQ
authors.lastname: Zhao
authors.forename: Yuan-Ming
authors.initials: YM
authors.lastname: Sun
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Zhang
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Huang
authors.forename: Hou-Rui
authors.initials: HR
authors.lastname: Zhang
authors.forename: Zhen-Yu
authors.initials: ZY
authors.lastname: Zhu
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D002846:Chromatography, Affinity; D002847:Chromatography, Agarose; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005506:Food Contamination; D005638:Fruit; D007306:Insecticides / Q000276:immunology*; D009946:Organothiophosphorus Compounds / Q000276:immunology*; D010573:Pesticide Residues / Q000032:analysis* / Q000276:immunology; D014675:Vegetables
chemical_list: D000911:Antibodies, Monoclonal; D007306:Insecticides; D009946:Organothiophosphorus Compounds; D010573:Pesticide Residues; C014655:methamidophos