title: Comparison of high performance liquid chromatography, radio immunoassay and electrochemiluminescence immunoassay for quantification of serum 25 hydroxy vitamin D.
abstract: OBJECTIVE
  To compare the performance of radioimmunoassay (RIA) with high-performance liquid chromatography (HPLC) and electrochemiluminescence (ECLIA) for the quantification of vitamin D (25OHD).
  
  
  METHODS
  HPLC method for the determination of 25OHD in human biological samples was developed and compared in terms of accuracy and precision with a commercially available RIA assay. Performance of RIA assay with ECLIA technology for 25OHD analysis was further compared.
  
  
  RESULTS
  Median 25OHD levels with HPLC vs. RIA were 50.1nmol/L (IQ=17.7-199.4nmol/L) and 51.1nmol/L (IQ=12.5-187.2nmol/L) respectively, whereas median 25OHD concentration with RIA vs. ECLIA was 32.4nmol/L (9.98-199.7nmol/L) and 29.9nmol/L (4.9-214.6nmol/L), respectively. Comparison data for HPLC vs. RIA showed RIA=-1.13+1.01 (HPLC) (RMSE=11.2nmol/L) and for RIA vs. ECLIA revealed, ECLIA=3.21+0.9 (RIA) (RMSE9.6nmol/L).
  
  
  CONCLUSIONS
  Acceptable correlation was observed among HPLC and RIA and also with RIA and ECLIA in quantification of 25OHD.
authors.affiliation: Department of Pathology & Microbiology, Aga Khan University, Pakistan.
authors.forename: Lena
authors.initials: L
authors.lastname: Jafri
authors.forename: Aysha Habib
authors.initials: AH
authors.lastname: Khan
authors.forename: Anwar A
authors.initials: AA
authors.lastname: Siddiqui
authors.forename: Shamim
authors.initials: S
authors.lastname: Mushtaq
authors.forename: Romaina
authors.initials: R
authors.lastname: Iqbal
authors.forename: Farooq
authors.initials: F
authors.lastname: Ghani
authors.forename: Imran
authors.initials: I
authors.lastname: Siddiqui
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods*; D006801:Humans; D008163:Luminescent Measurements / Q000379:methods*; D011863:Radioimmunoassay / Q000379:methods*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D