Analysis of lipoproteins using polyacrylamide gel electrophoresis and fractionated precipitation with polyanions and detergents. Use in the classification of hyperlipoproteinemias]

Sodium dodecylsulphate precipitates very low density lipoproteins (VLDL and chylomicrons) rich in triglyceride and a narrow correlation (r = 0.9) was found between the turbidimetric index SDS and triglyceridemia. Heparin in calcium medium acts in the same way and precipitates also low density lipoproteins (LDL) rich in cholesterol. A correlation (r = 0.875) was drawn up between the cholesterol LDL and the difference between the turbidimetric indices (heparin Ca -- SDS). In the first case, we were thus measuring by turbidimetry a VLDL + chylomicron index and, in the second case, an LDL index which permits one to obtain simplified typing of the hyperlipoproteinemias. A nomogram linking the two indices of hyperlipoproteinemia type was drawn up experimentally. This orientation analysis may be completed by electrophoresis on polyacrylamide gel used in concentration gradient and pH. In the system proposed, the lipoproteins were previously stained with tetrazolium nitroblue and clearly shown up. The chylomicrons in particular, become separated from the VLDL, the sinking pre-beta-lipoprotein or Lp (a) was identifiable and the type III hyperlipemia was easily diagnosed.