Manual
Procedure
Cat. No. 12240
For 50 tests
R 1 x 50 ml LDL- Cholesterol
Precipitation method
Cat. No. 12241 R 2 x 50 ml
For 100 tests
Liquid Reagent
Test Principle Assay
LDL- Cholesterol forms a precipitate by the action of the precipitating
reagent heparin on the serum. The supernatant contains VLDL and Blank Standard Sample
HDL-Cholesterol which are measured by the use of the Cholesterol
CHOD/ PAP method. LDL-Cholesterol is equal to the difference Distilled water 100 l -- --
between total cholesterol and cholesterol in the supernatant.
Concentrations in the test Standard -- 100 l --
Precipitating Reagent R : Supernatant -- -- 100 l
Citrate buffer solution pH = 5.04 64.0 mmol/L
Cholesterol working
Heparin ≥ 50 KU/L 1000 l 1000 l 1000 l
reagent
Standard : The Concentration as indicated on vial.
Mix. Incubate for 5 min. at 37°C or 10 min. at 20 - 25 °C. Read the
Stability of reagent absorbance (A) against reagent blank. The color is stable for 30
Precipitating reagent R: liquid, ready to use. min.
The reagent is stable up to expiry date given on the label when Calculation
stored A Sample
at +2 +8 °C. Cholesterol concentration in supernatant = X Conc.Standard
A Standard
Note: Don’t use if crystals sediment appear in the reagent.
LDL- Cholesterol (mg/dl) =
Additional requirement but not provided :
Cholesterol reagent Cat. No.12211,12212 or 12213. Total Cholesterol – (Cholesterol concentration in the supernatant x 11*)
Specimen collection and handling Note: 11* is the dilution factor of sample with precipitant.
1. Serum, heparinized or EDTA plasma.
2. Patient should be fasting 12 – 14 hours before the sample is taken. X 38.7
3. LDL in serum is reported stable for 7 days at 2 - 8 °C, and for 3 mmol/L mg/dl
months when frozen at - 20°C, and properly protected against evapo- 0.0259 X
ration.
Linearity
Standard Up to 300 mg/dl (7.77 mmol/L) .
LDL-Cholesterol STD. Cat. No. 16261 If the result exceeds 300 mg/dl or supernatant is turbid repeat the
Quality control test using diluted sample (1+1) with sodium chloride solution (0.9 %)
Meditrol lipids N Cat. No. 15211 and multiply the result by 2.
Meditrol lipids P Cat. No. 15221
Interferences
Precipitation Triglycerides: No significant interference up to 400 mg/dl.
Sample 100 l Precaution
Don’t pipette by mouth.
Precipitating Reagent 1000 l
Mix, incubate for 10 min. at 20 - 25 °C. Reference range
Centrifuge for 10 min. at a minimum of 4000 rpm. ≤4 wk. 50 - 170 mg/dl
Separate supernatant within 1 hour and use it for test. 2 - 12 mth. 60 - 190 mg/dl
Total Cholesterol
Note: Turbid supernatant has to be diluted (1+1) with sodium CHOD – PAP ≥1 yr. 110 - 230 mg/dl
chloride solution (0.9 %). Multiply result by 2.
Adults < 200 mg/dl
Determination of LDL- Cholesterol
Please prepare the cholesterol working reagent as specified in the HDL- Cholesterol Adults > 35 mg/dl
package insert of the cholesterol kits.
LDL- Cholesterol Adults < 155 mg/dl
Procedure
Wavelength Hg 546 (540 - 560 nm) References
Spectrophotometer 550 nm 1. Assmann, G. Internist, 20, (1979) , 559.
Cuvette 1 cm light path 2. Lopez-virellu, M. F., Clin. Chem., 23, (1977) , 882.
Temperature 37°C / 20 - 25°C 3. Young, DS., Effects of Drugs on Clinical Laboratory Tests, fifth edi-
Measurement against reagent blank tion 2000, AACC Press, Washington, D.C.
Reaction .end point
In vitro diagnostics First edition 2010
Medichem Middle East
Aleppo, Syria, E-mail: info@medichem-me.com
