title: Determination of calprotectin in gingival crevicular fluid by immunoassay on a microchip.
abstract: OBJECTIVE
  Gingival crevicular fluid (GCF) contains calprotectin, which appears to be a useful biomarker for periodontal diseases because of its high level in GCF from periodontally diseased pockets. To determine calprotectin in GCF that has a very small volume, sandwich enzyme-linked immunosorbent assay (ELISA) on a microchip was performed and its utility was estimated.
  
  
  METHODS
  Anti-calprotectin primary antibody was discharged on a microchip using a piezoelectric inkjet printing system. Calprotectin standard and calprotectin in GCF samples from eleven subjects were determined by the ELISA method with the prepared microchip and their values were compared with those obtained by conventional ELISA.
  
  
  RESULTS
  Using the ELISA on a microchip, a reasonable standard curve of calprotectin protein (1.56-100 ng/mL) was obtained. Calprotectin in GCF samples was quantified and showed reasonable values in accordance with the condition of periodontal diseases. The values determined by the microchip method and conventional ELISA showed a significant linear relationship (R(2)=0.981).
  
  
  CONCLUSIONS
  Calprotectin in GCF was determined using the ELISA on a microchip with high efficiency and this ELISA method for calprotectin determination may become a useful method for diagnosing periodontal diseases.
authors.affiliation: Department of Periodontology and Endodontology, Institute of Health Biosciences, The University of Tokushima Graduate School, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan. kido@dent.tokushima-u.ac.jp
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Kido
authors.forename: Kaori
authors.initials: K
authors.lastname: Abe
authors.forename: Shouki
authors.initials: S
authors.lastname: Yatsushiro
authors.forename: Mika
authors.initials: M
authors.lastname: Bando
authors.forename: Yuka
authors.initials: Y
authors.lastname: Hiroshima
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Nagata
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Ooie
authors.forename: Masato
authors.initials: M
authors.lastname: Tanaka
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kataoka
mesh_terms: D000368:Aged; D055910:Antibodies, Immobilized / Q000737:chemistry; D002138:Calibration; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards; D005260:Female; D005883:Gingival Crevicular Fluid / Q000378:metabolism*; D006801:Humans; D056656:Lab-On-A-Chip Devices; D039841:Leukocyte L1 Antigen Complex / Q000378:metabolism*; D016014:Linear Models; D008297:Male; D046210:Microfluidic Analytical Techniques; D008875:Middle Aged; D010510:Periodontal Diseases / Q000175:diagnosis / Q000378:metabolism; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D055910:Antibodies, Immobilized; D039841:Leukocyte L1 Antigen Complex