Neutrophil gelatinase-associated lipocalin (NGAL): validation of commercially available ELISA.

Author(s): Pedersen KR, Ravn HB, Hjortdal VE, Nørregaard R, Povlsen JV

Publication: Scand J Clin Lab Invest, 2010, Vol. 70, Page 374-82

PubMed ID: 20509756 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine the effects of delayed centrifugation, hemolysis, freeze-thaw cycling and storage at -80 degrees C on measurement of NGAL in lithium-heparin-plasma from a healthy adult and children with congenital heart disease. Pipette tips were used to induce low to moderate hemolysis in some specimens while others were lowered into liquid nitrogen twice to induce severe hemolysis. All specimens were frozen at -80 degrees C prior to analysis.

   Summary of Findings:

   Refrigerated storage of 6 blood specimens for up to 48 h before centrifugation and freezing had no effects on the measured levels of NGAL in plasma. Freeze-thaw cycling of 9 plasma specimens and storage of a single plasma pool at -80 degrees C for 11 months had no effects on the measured NGAL levels. NGAL concentrations were higher on the left side of the ELISA plate then on the right. Increasing hemolysis interfered with the NGAL ELISA causing an elevation in measured NGAL levels.

   Biospecimens

   • Bodily Fluid - Blood
   • Bodily Fluid - Plasma

   Preservative Types

   • Frozen

   Diagnoses:

   • Cardiovascular Disease
   • Normal

   Platform:

   Analyte	Technology Platform
   Protein	ELISA

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Storage duration	0 h 24 h 48 h 1 month 2 months 3 months 4 months 5 months 6 months 7 months 8 months 9 months 10 months 11 months
   ELISA Specific	Targeted peptide/protein	NGAL
   ELISA Specific	Specimen position	Left side of plate Right side of plate
   Storage	Freeze/thaw cycling	1 cycle 2 cycles 10 cycles
   Biospecimen Aliquots and Components	Hemolysis	Not induced Pipette tip-induced Liquid nitrogen-induced
   Biospecimen Aliquots and Components	Centrifugation	Centrifugation delays investigated

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2. Study Purpose

   The purpose of this study was to determine the effects of delayed centrifugation and freeze-thaw cycling on measurement of NGAL in urine from a healthy adult and children with congenital heart disease. All specimens were frozen at -80 degrees C prior to analysis.

   Summary of Findings:

   Refrigerated storage of 6 urine specimens for up to 48 h before centrifugation and freezing had no effects on the measured levels of NGAL. Further, up to 10 freeze-thaw cycles had no effect on the measured levels of NGAL in 9 urine specimens.

   Biospecimens

   • Bodily Fluid - Urine

   Preservative Types

   • Frozen

   Diagnoses:

   • Cardiovascular Disease
   • Normal

   Platform:

   Analyte	Technology Platform
   Protein	ELISA

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Freeze/thaw cycling	1 cycle 2 cycles 10 cycles
   Storage	Storage duration	0 h 24 h 48 h
   ELISA Specific	Targeted peptide/protein	NGAL

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