Clinical performance evaluation of total protein measurement by digital refractometry and characterization of non-protein solute interferences
| Autor: | Jonathan R. Genzen, Joshua J.H. Hunsaker, Sara P. Wyness, Taylor M. Snow |
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| Jazyk: | angličtina |
| Předmět: |
030213 general clinical medicine
Serial dilution TRIG triglycerides Clinical Biochemistry Analytical chemistry Biuret CSF cerebrospinal fluid 0403 veterinary science lcsh:Chemistry NaCl sodium chloride 0302 clinical medicine ddH2O demineralized distilled water LOQ limit of quantitation Total protein lcsh:R5-920 Radiological and Ultrasound Technology medicine.diagnostic_test Chemistry Monoclonal gammopathy GLU glucose Clinical performance TAE total allowable error TP total protein 04 agricultural and veterinary sciences Biuret test SG specific gravity Serum protein electrophoresis Total protein measurement lcsh:Medicine (General) Refractometry TE total error IRB Institutional Review Board 040301 veterinary sciences Article PT proficiency testing 03 medical and health sciences Refractometer medicine CAP College of American Pathologists ALB albumin BILI bilirubin ARUP Associated Regional & University Pathologists Chromatography CLSI Clinical & Laboratory Standards Institute CV coefficient of variation QC quality control Digital refractometry lcsh:QD1-999 RI reference interval SD standard deviation AMR analytical measurement range Hb hemoglobin |
| Zdroj: | Practical Laboratory Medicine, Vol 6, Iss, Pp 14-24 (2016) Practical Laboratory Medicine |
| ISSN: | 2352-5517 |
| DOI: | 10.1016/j.plabm.2016.08.001 |
| Popis: | Objectives: Refractometric methods to measure total protein (TP) in serum and plasma specimens have been replaced by automated biuret methods in virtually all routine clinical testing. A subset of laboratories, however, still report using refractometry to measure TP in conjunction with serum protein electrophoresis. The objective of this study was therefore to conduct a modern performance evaluation of a digital refractometer for TP measurement. Design and methods: Performance evaluation of a MISCO Palm Abbe™ digital refractometer was conducted through device familiarization, carryover, precision, accuracy, linearity, analytical sensitivity, analytical specificity, and reference interval verification. Comparison assays included a manual refractometer and an automated biuret assay. Results: Carryover risk was eliminated using a demineralized distilled water (ddH2O) wash step. Precision studies demonstrated overall imprecision of 2.2% CV (low TP pool) and 0.5% CV (high TP pool). Accuracy studies demonstrated correlation to both manual refractometry and the biuret method. An overall positive bias (+5.0%) was observed versus the biuret method. On average, outlier specimens had an increased triglyceride concentration. Linearity was verified using mixed dilutions of: a) low and high concentration patient pools, or b) albumin-spiked ddH2O and high concentration patient pool. Decreased recovery was observed using ddH2O dilutions at low TP concentrations. Significant interference was detected at high concentrations of glucose (>267 mg/dL) and triglycerides (>580 mg/dL). Current laboratory reference intervals for TP were verified. Conclusions: Performance characteristics of this digital refractometer were validated in a clinical laboratory setting. Biuret method remains the preferred assay for TP measurement in routine clinical analyses. Keywords: Refractometry, Digital refractometry, Total protein, Biuret, Serum protein electrophoresis, Monoclonal gammopathy |
| Databáze: | OpenAIRE |
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