title: Syringe-push membrane absorption as a simple rapid method of urine preparation for clinical proteomics.
abstract: BACKGROUND
  The analysis of urinary proteome might reveal biomarkers of clinical value. However, current methods of urine preparation for down-stream proteomic analysis are complicated, time-consuming, and/or expensive. This study aims to develop a robust, simple, inexpensive and readily accessible urine preparation method to facilitate clinical proteomic workflow.
  
  
  RESULTS
  Syringe-push membrane absorption (SPMA) was successfully developed by a combination of 5-ml medical syringe and protein-absorbable membrane. Comparing three membranes i.e., nitrocellulose, polyvinylidene difluoride (PVDF) and Whatman no.1, nitrocellulose combined with SPMA (nitrocellulose-SPMA) provided the greatest quality of proteome profile as demonstrated by 2-DE. The quality of the proteome profile and the performance of nitrocellulose-SPMA were systematically compared with three current methods of urine preparation (i.e., ultrafiltration, dialysis/lyophilization and precipitation). While different methods of urine preparation provided comparable proteome quality, nitrocellulose-SPMA had better working performance due to acceptable recovery yield, less workload, short working time, high accessibility and low unit cost. In addition, protein absorbed on nitrocellulose harvested from the SPMA procedure could be stored as a dried membrane at room temperature for at least 1-month without protein degradation or modification.
  
  
  CONCLUSIONS
  SPMA is a simple rapid method of preparing urine for downstream proteomic analysis. Because of it is highly accessible and has long storage duration, this technique holds potential benefit for large-scale multi-center research and future development of clinical investigation based upon urinary proteomic analysis.
authors.affiliation: Central Laboratory, Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Somchai
authors.initials: S
authors.lastname: Chutipongtanate
authors.affiliation: Hematology and Oncology Unit, Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Channarong
authors.initials: C
authors.lastname: Changtong
authors.affiliation: Laboratory of Biochemistry, Chulabhorn Research Institute, Bangkok, Thailand.
authors.forename: Churat
authors.initials: C
authors.lastname: Weeraphan
authors.affiliation: Hematology and Oncology Unit, Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Suradej
authors.initials: S
authors.lastname: Hongeng
authors.affiliation: Laboratory of Biochemistry, Chulabhorn Research Institute, Bangkok, Thailand.
authors.forename: Chantragan
authors.initials: C
authors.lastname: Srisomsap
authors.affiliation: Laboratory of Biochemistry, Chulabhorn Research Institute, Bangkok, Thailand ; Applied Biological Sciences Program, Chulabhorn Graduate Institute, Bangkok, Thailand.
authors.forename: Jisnuson
authors.initials: J
authors.lastname: Svasti
keywords: Comparison; Membrane absorption; Proteomics; Urine preparation