title: [Pretreatment methods of urine proteomics in children with primary nephrotic syndrome].
abstract: OBJECTIVE
  To optimize a pretreatment method of urine proteomics in children with primary nephrotic syndrome.
  
  
  METHODS
  Urine from children with primary nephrotic syndrome was treated in different pH and isolated by cold acetone precipitation for different durations. Then the amounts and kinds of proteins were compared by quantify, SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional electrophoresis (2-DE) in order to optimize a way to deal with urine protein.
  
  
  RESULTS
  Most proteins were obtained at pH 2.7. The amounts of protein precipitated by acetone for 0.5 hr was obviously less than those precipitated for 1 and 2 hrs (P<0.05), while there was no significant difference between the amount of protein precipitated for 1 and for 2 hrs. Protein precipitated by cold acetone for 1 hr at pH 2.7 was selected as the best pretreatment method. Satisfactory 2-DE maps can be acquired.
  
  
  CONCLUSIONS
  Urine protein can be best obtained at pH 2.7 and precipitated by cold acetone for 1 hr.
authors.affiliation: Department of Nephrology, Teaching Hospital, Capital Institute of Pediatrics, Peking University, Beijing 100020, China.
authors.forename: Qiu-Xia
authors.initials: QX
authors.lastname: Wang
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Cao
authors.forename: Bo
authors.initials: B
authors.lastname: Niu
authors.forename: Guo-Liang
authors.initials: GL
authors.lastname: Wang
authors.forename: Ru-Gang
authors.initials: RG
authors.lastname: Zhong
mesh_terms: D002648:Child; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009404:Nephrotic Syndrome / Q000652:urine*; D011507:Proteinuria / Q000652:urine*; D040901:Proteomics / Q000379:methods*