Reagent for Lipase

Intended Use: This reagent kit is used for the in-vitro quantitative determination of Lipase in human serum/plasma.

Pack size: 1 × 12 ml

Shelf life: 18 months

Storage: 2°–8°C

Product overview

This Lipase (Colorimetric method) Liquid Reagent is a photometric assay based on lipase-specific degradation of a chromogenic substrate (DGGR/DGGMR) to produce methylresorufin, which is measured photometrically. Lipase activity is proportional to methylresorufin production.

For general information on serum lipase testing, see MedlinePlus: Lipase Tests

Quick facts

• Method: Fixed Time (2-point), colorimetric
• Wavelength: 578 nm
• Assay temperature: 37°C
• Sample: Serum / plasma (heparinised; IFU also references EDTA plasma)
• Sample stability: up to 5 days at 2–8°C or 24 hours at 20–25°C
• Linearity: up to 250 U/L
• Limit of quantitation (LoQ): 5 U/L

Intended use

This reagent kit is used for the in-vitro quantitative determination of Lipase in human serum/plasma.

Test principle

The colorimetric method is based on lipase-specific degradation of a chromogenic substrate (DGGR/DGGMR). The substrate is cleaved by lipase to form an intermediate that decomposes in alkaline solution to produce methylresorufin. Lipase activity is determined photometrically based on methylresorufin production.

Kit contents

• Reagent 1: R1 Lipase Reagent
• Reagent 2: R2 Lipase Reagent
• Reagent 3: Calibrator (value is mentioned on the vial label)

Working reagent preparation

The assay can be performed using separate R1 and R2, or using a working reagent. For working reagent preparation, mix gently 5 parts of R1 and 1 part of R2. Use freshly prepared working reagent.

Specimen collection and storage

• Specimen: serum or plasma (heparinised plasma free from haemolysis; IFU also references EDTA plasma)
• Stability: up to 5 days at 2–8°C or 24 hours at 20–25°C
• It is recommended to perform the assay with freshly collected samples.

Manual test procedure (summary)

Assay conditions: Wavelength 578 nm; Temperature 37°C. Bring reagents and samples to room temperature (21–25°C) before the assay.

Pipette into the tube:

• R1 Lipase Reagent: 1000 µl (Calibrator and Test)
• R2 Lipase Reagent: 200 µl (Calibrator and Test)
• Then add:
• R3 Calibrator: 10 µl (Calibrator)
• Sample: 10 µl (Test)

Mix well. After exactly 60 seconds, read absorbance A1 of Test and Calibrator against air or water. In the next 60 seconds, repeat to obtain A2, then calculate ΔA = (A2 – A1) for test and calibrator.

System parameters 

• Method: Fixed Time (2-point)
• Wavelength: 578 nm
• Zero setting: Distilled water
• Delay time: 60 seconds
• Read time: 60 seconds
• No. of readings: 2
• Units: U/L
• Reaction slope: Increasing

Calculation

Lipase activity [U/L] = ΔA (T) / ΔA (C) × Calibrator concentration

Normal values

5–60 U/L

It is recommended that each laboratory establish its own normal range.

Performance characteristics 

• Limit of quantitation (LoQ): 5 U/L
• Linearity: up to 250 U/L. If sample activity exceeds 250 U/L, dilute with 0.9% NaCl, repeat the assay, and multiply by the dilution factor.
• Interferences: haemoglobin up to 2.5 g/dl, bilirubin up to 20 mg/dl, triglycerides up to 500 mg/dl, ascorbate up to 62 mg/l do not interfere with the test.

Quality control

Each run should include assayed normal and abnormal controls. If commercial controls are not available, known-value samples may be aliquoted, frozen, and used as controls.

Precautions (selected)

• Store reagents at 2–8°C and do not freeze or expose to higher temperature.
• Bring reagents to room temperature before the assay.
• Avoid contamination of reagents during assay process; use clean glassware.

Frequently Asked Questions

What is this reagent used for?

It is used for the in-vitro quantitative determination of Lipase in human serum/plasma.

What wavelength is used?

578 nm.

What is the measuring range stated in the IFU?

The method is linear up to 250 U/L.

What sample types can be used?

Serum or plasma (heparinised; IFU also references EDTA plasma).

What interferences are stated in the IFU?

Haemoglobin up to 2.5 g/dl, bilirubin up to 20 mg/dl, triglycerides up to 500 mg/dl, and ascorbate up to 62 mg/l do not interfere with the test.