INTRODUCTION
Neutrophil gelatinase-associated lipocalin (NGAL), also known as Lipocalin-2 (LCN2), is a protein expressed in neutrophils and in the kidney at low levels in healthy subjects. During acute kidney injury (AKI), NGAL is secreted at high levels into the bloodstream and urine within 2 hours of injury. Therefore, NGAL is a more accurate and sensitive biomarker for diagnosing AKI than serum creatinine. In fact, the increase in urinary excretion of NGAL has been proven to be due to tubular alterations that take place well before any damage can be detected by other methods. Therefore, monitoring NGAL levels reduces delayed AKI diagnosis and treatment. NGAL can also be used as an early biomarker for diagnosis of chronic kidney disease, contrast-induced nephropathy and diabetic nephropathy. The reference value of the NGAL in plasma is < 180 ng/mL.
PRINCIPLE OF THE ASSAY
This assay is a turbidimetric immunoassay for the quantitative measurement of NGAL in human plasma and urine. A standard or sample is added into a cuvette and mixed with the reaction buffer R1. After a short incubation, the test reagent R2, which is a suspension of microparticles coated with NGAL antibodies, is added into the cuvette and mixed. The presence of NGAL in the standard or sample causes the immune-particles to aggregate. The extent to which the microparticles aggregate is quantified by the amount of light scattering measured as absorbance by a chemistry analyzer. The concentration of NGAL in unknown samples can be interpolated from a reference curve using the standards provided.
PERFORMANCE OF THE KIT
TYPICAL STANDARD CURVE
NGAL (ng/mL) Absorbance (570 nm) 0 -0.0068 100 0.0085 250 0.0354 1000 0.1988 2500 0.5002 5000 0.6786 ASSAY PROCEDURE
Assay procedures may vary depending on the automated chemistry analyzer to be used. A general example of assay procedures is stated as follow:
1. Dispense 150µl of R1 into a clean cuvette
2. Add 1.5µl of sample and incubate at 37˚C for 5 minutes
3. Further add 50µl of R2
4. Read change of absorbance at 570 nm for 8 minutes after the addition of R2
5. Calculate the concentration of NGAL in unknown sample by interpolation from a reference curve using the standards provided
OTHER MATERIALS REQUIRED
Product Catalog Number Format Calibrator 51050-S1 5 x 1ml Control 51050-C1 2 x 1ml
The package insert must be read in its entirety before using this product
Use only the current version of product data sheet enclosed with the purchased kit.
