Modified immunoblotting technique for phenotyping lipoprotein(a).

We describe a modified immunoblotting method for phenotyping lipoprotein(a) [Lp(a)]. This immunoblotting procedure uses commercially available reagents that have a long shelf life. The method is sensitive and takes only 18 microL of sera. Lp(a) phenotyping can be performed on sera stored at 4 degrees C for as much as a week or at -80 degrees C for as long as a year. In a study of 145 unrelated healthy subjects, we found Lp(a) allelic frequencies of LpF = 1.8%, LpB = 2.6%, LpS1 = 5.1%, LpS2 = 14.8%, LpS3 = 35.9%, LpS4 = 11.6%, and LpO = 28.0%.