Quantitative assay of α_E and β subunits in plasma: linear range of Western blot analysis. A plasma sample (adult) was diluted to the micrograms of total fibrinogen per lane as indicated on the abscissa, and analyzed by Western immunoblotting with either anti-VI or anti-β, as indicated. Integrated intensity of the single band obtained with each antibody, as quantified by computer analysis, is plotted on the ordinate.