calculated on the basis of difference between total cholesterol levels of serum and the
cholesterol levels in the supernatant after centrifugation.
35.5.2 Reagents
1.LDL-cholesterol precipitant: Stable for 4 weeks at 20– 25 C
2.Cholesterol reagent: Same as that used in cholesterol estimation
35.5.3 Procedure
Mix 200μl of serum with 100μl of precipitating reagent and allow standing for
15 min at room temperature and then centrifuge at 10000 rpm for 2 min or for 15 min
at 1500 rpm.
Take two test tubes, and mark them as test and blank. Add 25μl of supernatant in
tube labelled as test and 25μl of distilled water in blank tube. Add 1 ml of cholesterol
reagent to these tubes, mix, and incubate at 37C for 5 min or room temperature for
10 min. Measure absorbance at 500 nm against blank in a spectrophotometer, and
calculate the cholesterol value in the supernatant. From total cholesterol value, the
value obtained in the supernatant is subtracted to get the LDL cholesterol value.
LDL¼HDLþTriglycerides
5
Here triglyceride/5 gives VLDL value.35.6 Clinical Significance...............................
35.6.1 Cholesterol Levels
A cholesterol value below 200 mg/dl is always considered desirable and indicates a
low risk of heart disease. Cholesterol value above 240 mg/dl is considered high risk.
Cholesterol is high during pregnancy and up to 6 weeks after the baby is born. Some
drugs like anabolic steroids, epinephrine, oral contraceptives, and vitamin D are
known to increase cholesterol levels.
144 35 To Measure Lipid Profile in Serum Sample