Separation of fibrinogen species by Mono Q anion exchange chromatography . Human fibrinogen (fraction I-2) was purified from umbilical cord plasma and then subjected to column chromatography as described in “Materials and methods.” The elution profile is plotted with absorbance at 280 nm as a solid line (scale on the left), and the stepwise gradient in Tris phosphate is indicated by the broken line (scale on the right). The major and minor peaks are labeled A and B, respectively.