Characterization of commercial antibodies for use in high resolution apo(a) phenotyping by immunoblot analysis

High resolution apo(a) phenotyping has been used in conjunction with apo(a) genotyping to elucidate underlying mechanisms of plasma lipoprotein(a) (Lp(a)) level control. With increasing interest in this field more laboratories are now establishing such methods. High resolution apo(a) phenotyping has previously been reported with in-house monoclonal antibodies. Here the effective use of a commercially available monoclonal antibody is demonstrated. Two primary antibodies were compared and apo(a) isoform analysis was performed using an immunobloltting method. When equal quantities of Lp(a) were loaded approximately equal signal intensities were obtained, irrespective of apo(a) isoform size. Serial dilutions of samples with known Lp(a) level and a single expressing apo(a) isoform were used to determine the detection limit of the system. With both monoclonals it was possible to detect 0.05 mg/dl Lp(a).