HDL/LDL

• Both HDL/LDL are lipoproteins, makeup is different enough so same methodology cannot be used on both
• LDL - very similar to VLDL and IDL and chylomicrons; difficult to isolate LDL from other low density lipoproteins
• HDL - easier to isolate, has a lipoproteins; used to sequester HDL from other lipoproteins
• LDL’s - migrate with Beta in electrophoresis
• VLDL - migrate with pre-beta on electrophoresis
• HDL - migrate with alpha proteins on electrophoresis
• Electrophoresis - historical; chylomicrons don’t move, so band of chylomicrons stays at application pont
• • Immunochemistry - can isolate LDL’s using this method; not done often; expensive and unnecessary 
• • Direct HDL - remove other lipoproteins by absorbing them; then same method as total cholesterol is used
  • Dissolve HD lipoproteins and break them up
  • Cholesterol esters are in HDL
  • Really measuring cholesterol in HDL