Effect of manganese ions on HDL2 precipitation with dextran sulfate

The dual precipitation method involving the separation of HDL and HDL3 from normolipemic serum by heparin-MnCl2/dextran sulfate was evaluated with regard to the Mn2+ effect on HDL2 precipitation with dextran sulfate (DS) in the second precipitation step. Increased HDL2-C and HDL2-TAG values brought about by increased Mn2+ concentrations were found at all DS concentrations studied. The comparison of the lipid HDL2 and HDL3 values with those given by polyethylene glycol precipitation method yielded two optimal combinations of DS/Mn2+ concentrations: 1.11 g.l-1/0.076 mol.l-1 and 0.87 g.l-1/0.091 mol.l-1. The obtained results call attention to the importance of final concentration of Mn2+ ions at HDL2 precipitation with DS from heparin-Mn2+ supernate containing HDL.