title: Analytical evaluation of Diazyme procalcitonin (PCT) latex-enhanced immunoturbidimetric assay on Beckman Coulter AU5800.
abstract: BACKGROUND
  This study was aimed to evaluate the analytical performance of the novel Diazyme procalcitonin (PCT) immunoturbidimetric assay on Beckman Coulter AU5800.
  
  
  METHODS
  Diazyme PCT is a latex-enhanced immunoturbidimetric assay, developed for use on laboratory instrumentations with capability of reading absorbance at 600 nm. This analytical evaluation included the assessment of limit of blank (LOB), limit of detection (LOD), functional sensitivity, imprecision, linearity, carryover, and method comparison between Diazyme PCT and Kryptor PCT on 129 routine serum inpatient samples.
  
  
  RESULTS
  The LOB, LOD, and functional sensitivity of Diazyme PCT were 0.16, 0.26, and 0.28 ng/mL, respectively. The intra- and inter-assay imprecision of Diazyme PCT was between 2.9% and 7.8%. The linearity was excellent in the range of PCT values between 0.16 and 56 ng/mL, and the carryover was negligible (0.02%). A highly significant agreement was found between Kryptor PCT and Diazyme PCT in a range of concentrations between 0.16 and 111 ng/mL (Diazyme PCT=1.10×Kryptor PCT-0.89; r=0.960; p<0.001). The mean bias was 0.48 ng/mL (95% CI, -0.58 to 1.54 ng/mL). The strength of agreement between Kryptor PCT and Diazyme PCT was between 85% and 96% at 0.50, 2.0, and 10 ng/mL cutoffs.
  
  
  CONCLUSIONS
  Diazyme PCT appears to be a reliable assay for diagnosis and management of critical care patients susceptible to severe bacterial infections.
authors.forename: Mariella
authors.initials: M
authors.lastname: Dipalo
authors.forename: Ruggero
authors.initials: R
authors.lastname: Buonocore
authors.forename: Cecilia
authors.initials: C
authors.lastname: Gnocchi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Picanza
authors.forename: Rosalia
authors.initials: R
authors.lastname: Aloe
authors.forename: Giuseppe
authors.identifier: http://orcid.org/0000-0001-9523-9054
authors.initials: G
authors.lastname: Lippi
mesh_terms: D001774:Blood Chemical Analysis / Q000379:methods*; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D006801:Humans; D007297:Inpatients; D007840:Latex; D057230:Limit of Detection; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D011498:Protein Precursors / Q000097:blood*
chemical_list: C000606589:CALCA protein, human; D007840:Latex; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide