Zonal rotor ultracentrifugation: a proposal for improving the effectiveness of the procedure

A methodological variant of the zonal ultracentrifugation technique for the separation of plasma lipoproteins is described. The modification consists of (1) preloading the rotor with water and (2) using a different gradient former, and altering the gradient profile during the second step. This variant permits the detection of an intermediate lipoprotein even in healthy individuals and in cord blood.