Characterization of the RSA cDNA. The protein sequence corresponding to the mature, circulating RSA, deduced from the DNA sequence of p(alb)192, is shown in (A), aligned to its human counterpart. R, RSA; H, HSA. Double dots indicate identical, and single dots, similar residues; amino acid numbering is shown at the right. (B) An immunoblot stained with mono-specific anti-RSA antibodies. Lane Se, conditioned media from Cos cells transfected with pSG5-RSA (sense orientation); lane As, equivalent amount of conditioned media from cells transfected with pSG5-ASR (antisense orientation). M, prestained low-molecular-weight range markers (BioRad); Co, positive control (250 ng purified plasma-derived RSA).