Cholesterol Clinical Chemistry

Cholesterol Reagents – Quantitative Measurement of Total Cholesterol

The Cholesterol Reagents kit is designed for the in-vitro quantitative determination of total cholesterol in human serum and plasma. This enzymatic test is essential for clinical laboratories conducting lipid profiling and cardiovascular risk assessments.

For full instructions, refer to the Cholesterol Reagents IFU.

Intended Use

This reagent kit is used for the in-vitro quantitative determination of total cholesterol in human serum and plasma samples.

Test Principle

This test is based on the enzymatic colorimetric method modified from the procedure by Allain et al. and Roschlau et al. The process includes:

1. Cholesterol esterase hydrolyses cholesterol esters into free cholesterol and fatty acids.

2. Cholesterol oxidase (CHOD) oxidises free cholesterol to cholest-4-en-3-one and hydrogen peroxide.

3. Peroxidase (POD) reacts with hydrogen peroxide, 4-aminoantipyrine, and phenol to form a red quinoneimine dye.

The intensity of the dye is measured at 500 nm and is directly proportional to the total cholesterol concentration in the sample.

Reaction Sequence

Cholesterol esterase:

Cholesterol esters + H₂O ⟶ Cholesterol + Fatty acids

Cholesterol oxidase (CHOD):

Cholesterol + O₂ ⟶ Cholest-4-en-3-one + H₂O₂

Peroxidase (POD):

2 H₂O₂ + 4-AAP + Phenol ⟶ Quinoneimine dye (Red) + 4 H₂O

Performance Characteristics:

• Measurement Wavelength: 500 nm

• Assay Type: Enzymatic colorimetric

Kit Contents

• Reagent 1: Cholesterol Enzyme Reagent

• Reagent 2: Cholesterol Standard (200 mg/dL)

• Product Insert: 1 copy

All reagents are ready to use and should be stored at 2–8°C.

Storage & Stability

• Unopened reagents are stable until the expiry date if stored between 2–8°C.

• Do not freeze or expose reagents to high temperatures.

• All reagents are liquid and stable under recommended conditions.

Specimen Collection & Handling

• Recommended sample: unhemolysed fasting serum.

• Heparinised plasma may also be used.

• Cholesterol in serum is stable for 7 days at room temperature and up to 6 months when frozen, if protected from evaporation.

• Avoid hemolysis and improper storage conditions.

Precautions

1. Follow storage instructions carefully.

2. Do not freeze reagents.

3. Avoid exposure to heat.

4. Use fresh and properly stored samples for reliable results.

Frequently Asked Questions (FAQs)

1. What is the Cholesterol Reagent Kit used for?

It is used for the quantitative estimation of total cholesterol in serum and plasma.

2. What method does the kit use?

The test uses a modified enzymatic colorimetric method involving cholesterol esterase, cholesterol oxidase, and peroxidase.

3. What sample types are accepted?

The kit is validated for use with serum (preferably fasting) and heparinised plasma.

4. How should the kit be stored?

Store all reagents at 2–8°C. Do not freeze.

5. Where can I find the complete instructions for use (IFU)?

Access the full IFU here.