Until recently, the characterization of genetic variants of human serum albumin was performed by electrophoretic typing prior to the determination of their amino acid substitutions. We describe a procedure using isoelectric focusing in the presence of urea for the analysis of the genetic variation of albumin. This procedure allowed a clear distinction of a new variant, previously found to be identical with albumin Sondrio according to its relative electrophoretic mobilities at 3 pHs. This new variant, the third rare albumin allotype identified in the Ile-de-France region, was called albumin Paris 2.