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The Emit® 2000 Cyclosporine Specific Assay, Extended Range: Development of an application protocol for the V‐Twin® Analyzer
Author(s) -
Morjaihmat,
Yau Harriet,
Rea Diane,
Ruttle Doris,
Jones Heather,
Siefring Jr. Gerald,
Christenson Robert
Publication year - 2011
Publication title -
biotechnology and applied biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.468
H-Index - 70
eISSN - 1470-8744
pISSN - 0885-4513
DOI - 10.1002/bab.43
Subject(s) - chromatography , chemistry , metabolite , tandem mass spectrometry , spectrum analyzer , liquid chromatography–mass spectrometry , whole blood , mass spectrometry , medicine , biochemistry , electrical engineering , engineering
We evaluated a new protocol for measurement of cyclosporine A (CsA) 2 H after dose (C2) on the V‐Twin® analyzer. Imprecision, recovery, and linearity were determined using CsA‐spiked blood pools. Accuracy was evaluated using specimens from renal, cardiac, and liver transplant patients, and results were compared with those from liquid chromatography–tandem mass spectrometry (LC–MS/MS) and the Abbott TDx®/TDxFLx® assay. Cross‐reactivity and interferences were assessed in the presence of 800 ng/mL CsA. Imprecision coefficients of variation were 3.3%–4.8% (within run) and 5.9%–8.7% (total). Recovery was within 10% of the expected values. Linearity was 350–2,000 ng/mL. Calibration was stable for ≥ 2 weeks. Method comparison showed regression statistics: V‐Twin® = 1.01 × LC tandem MS + 36.1, r = 0.971; V‐Twin® = 1.13 × Abbott − 92.4, r = 0.969. Metabolite cross‐reactivity and interference (endogenous substances and drugs) were within ±10%. The C2 protocol on the V‐Twin® analyzer provides acceptable assay performance and accurate determination of whole blood CsA drawn at 2 H after dose.