Fig 1.

Preparative IEF fractionation of plasma IgG with broad HIV neutralizing activity. Representative data from subject 6 (see the text) are shown. Fractionation of 20 mg IgG was achieved by preparative IEF with a pH range of 6.5 to 9.5 (indicated at bottom), as described in Materials and Methods. An aliquot of each fraction (10 μl) was electrophoresed over an IEF gel with a pH range of 6 to 11 (indicated at left). Immunoglobulin bands were visualized with silver stain. Lanes 1 to 20 correspond to fractions 1 to 20, respectively.