Technical Summary: Cholesterol Analysis (Bulletin ref. TB018812F)
 

A fast enzymatic assay for plasma cholesterol using Cholesterol Oxidase.
 

Name:
Codes:

Cholesterol
GMRD-084 (50 tests)
GMRD-084J (8 x 50 tests)
 

Instruments:
 

All GM7/GL5 Series analysers
 

Principle:

i) Cholesterol esters are converted to free cholesterol in a brief pre-reaction:
 

ii) In the presence of molecular oxygen, cholesterol is oxidised by the enzyme cholesterol oxidase to cholestenone and hydrogen peroxide:
 

Under the conditions of the assay, oxygen consumption is directly proportional to cholesterol concentration.
 

Samples:
Sample volume:
Linearity:
Precision:
Accuracy:
 

Plasma or serum. Whole blood for screening only.
3.5 µl
10 mmol/L (387 mg/dl)
Typical within-run C.V. 1 % @ 5 mmol/L
y (Analox) = 0.98 (Manual enzymatic) + 0.04 mmol/L, r = 0.988, n = 142
 

Reagent Stability:

Shelf life 6 months unopened when stored at 0 - 5°C. Reconstituted cholesterol oxidase enzyme, 7 - 10 days if stored at 0 - 5°C.
 

Notes:

i) Whole blood cholesterol values are lower than plasma or serum by on average 15 - 20 %.
ii) Analysis of High Density Lipoprotein (HDL) cholesterol fraction can be performed using Analox HDL microtubes, code: GMRD-089
iii) An alternative assay for cholesterol using end-point determination is available on the GM7 analyser - contact Analox for details.