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VETSPEC™REAGENTS - Lipase

Intended Use

For IN VITRO diagnostic use in the quantitative determination of Lipase in serum using manual or automated applications.

Method Principle

Human pancreatic lipase catalyzes a two-step reaction: 1,2-diglyceride is hydrolyzed to 2-monoglyceride and fatty acids. The 2-monoglyceride is further hydrolyzed by monoglyceride lipase (MGLP) to glycerol and fatty acids. Glycerol is then quantitated using a first order rate GPO-Trinder reaction. Absorbance changes are monitored at 550 nm. The reaction scheme below illustrates the reactions that take place in this method.

Lipase
     1,2-diglyceride + H2O ───────> 2-monoglyceride + FFA

          MGLP
2-monoglyceride + H2O ───────> Glycerol + FFA

GPO
              Glycerol-3-phosphatre + O2 ────> Dihydroxyketon-phosphate + H2O2

        Peroxidase
H2O2 + 4-aminoantipyrine + TOOS ────────> Quinonedimine-dye + 4H2O


Preparation Of Working Reagents

Catachem Lipase Working Enzyme Substrate Reagent (R1) is prepared by adding the 10 mL of Substrate Diluent to each Enzyme Substrate vial. The Activator Reagent (R2) is supplied ready for use. No preparation is required.

Reagent Storage And Stability

Catachem Lipase reagents are stored at 2-8°C. When stored as directed, these reagents are stable until the expiration date stated on the label. Catachem Lipase Working Reagents (R1 and R2) are stored at 2-8°C. When prepared and stored as directed, the Working Reagents are stable for 21 days at 2-8°C.

Method Performance Characteristics

Sensitivity: The sensitivity of this method is  0.008-0.0120 OD/U/L.
Linear Range: In this method there is no significant nonlinearity over the range of 0-600 U/L.
Precision Study:

Lipase

Serum Sample No. 1

Serum Sample No. 2

N

15

15

U/L

18.8

72.6

SD

2.1

2.1

% CV

0.92

0.92


Correlation

A comparison of this method using an automated analyzer was carried  out against a reference, UV, kinetic method. The performance of Catachem’s Lipase method was found essentially equivalent to the reference method used. Linear regression analysis produced the following information:

Correlation Data

Parameter

Data Observed

N

58

Regression

Y = 1.844x + 7.15

Correlation

r = 0.982