title: Comparison of the automated KRYPTOR chromogranin A assay with the DAKO ELISA.
abstract: BACKGROUND
  Currently available assays for the widely used marker for neuroendocrine tumors chromogranin A have a weak comparability, involve manual work, and require batch processing of the samples. In this study, we evaluated the automated chromogranin A KRYPTOR assay compared with the widely used DAKO ELISA.
  
  
  METHODS
  83 samples were measured with the DAKO ELISA (EDTA plasma) and the KRYPTOR assay (serum), since different sample materials are recommended. Furthermore, different sample materials were compared.
  
  
  RESULTS
  The results between the two assays were highly correlated (KRYPTOR serum (ng/mL) = 2.887 ELISA EDTA (U/L) + 5.028; r = 0.99). The inter-assay variation for the KRYPTOR assay was determined as 5.56% at low (95 ng/mL; n = 34) and 6.21% at high (530 ng/mL; n = 33) chromogranin A concentrations. EDTA plasma samples revealed significantly lower results than serum in the KRYPTOR assays and could not be used.
  
  
  CONCLUSIONS
  In conclusion, the new chromogranin A KRYPTOR assay is fast, reliable, and compares well to an established test after adaptation of sample material and reported units.
authors: Magnus
authors: M
authors: Wolf
authors: Isolde
authors: I
authors: Riedlinger
authors: Rainer
authors: R
authors: Lehmann
authors: Hans-Ulrich
authors: HU
authors: Häring
authors: Erwin
authors: E
authors: Schleicher
authors: Andreas
authors: A
authors: Peter
mesh_terms: D057205:Automation, Laboratory; D014408:Biomarkers, Tumor / Q000097:blood*; D053379:Chromogranin A / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D011237:Predictive Value of Tests; D015203:Reproducibility of Results
chemical_list: D014408:Biomarkers, Tumor; C506150:CHGA protein, human; D053379:Chromogranin A