title: Multimeric stability of human C-reactive protein in archived specimens.
abstract: BACKGROUND
  C-reactive protein (CRP) is a marker of inflammation and a risk predictor of cardiovascular disease. Current CRP assays are focused on the quantification of the CRP levels as pentamers. However, CRP can be present as other multimeric forms. There will be a market need to measure the CRP multimeric structure in addition to the levels in human populations. To meet this need, we investigated whether the long-term archived samples could be used instead of freshly collected samples.
  
  
  RESULTS
  The specimens of serum, plasma and tissues were collected from transgenic rats expressing the human CRP. These samples were stored at 4°C, -20°C and -80°C for different periods. Non-denaturing Western blot analysis was used to observe the influence of storage conditions to multimeric structures of human CRP. Our results showed that there was no difference on multimeric structures of human CRP between samples stored at 4°C, -20°C and -80°C, between samples stored at -80°C for twenty-four hours and three months, and between plasma and serum.
  
  
  CONCLUSIONS
  This study implicated that archived samples stored at these conditions in those large longitudinal studies could be used for investigating the multimeric structures of CRP. Our report may speed up these researches and save labors and budget by enabling them to use currently available archived samples rather than freshly collected samples.
authors.affiliation: Department of Obstetrics and Gynecology, First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi, China.
authors.forename: Qiling
authors.initials: Q
authors.lastname: Li
authors.forename: Ting
authors.initials: T
authors.lastname: Kang
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Tian
authors.forename: Yamin
authors.initials: Y
authors.lastname: Ma
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Jendai
authors.initials: J
authors.lastname: Richards
authors.forename: Tameka
authors.initials: T
authors.lastname: Bythwood
authors.forename: Yueling
authors.initials: Y
authors.lastname: Wang
authors.forename: Xu
authors.initials: X
authors.lastname: Li
authors.forename: Dong
authors.initials: D
authors.lastname: Liu
authors.forename: Li
authors.initials: L
authors.lastname: Ma
authors.forename: Qing
authors.initials: Q
authors.lastname: Song
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002097:C-Reactive Protein / Q000737:chemistry / Q000378:metabolism*; D015925:Cryopreservation; D006801:Humans; D011487:Protein Conformation; D055503:Protein Multimerization; D055550:Protein Stability; D051381:Rats; D055647:Rats, Transgenic; D013696:Temperature; D013997:Time Factors; D014021:Tissue Preservation
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein