Fig. 2.
At least 2 serum components are required for rosette formation, as demonstrated using conA affinity chromatography.
(A) SDS-PAGE profile of fractions eluted from a conA–Sepharose affinity column. Aliquots of whole serum (WS) and conA-unbound (C1) and conA-bound, eluted (C2) fractions (up to 20 μg protein, corresponding to the same relative amount of each fraction) were resolved by SDS-PAGE (10% acrylamide) in the absence (nonreduced) or presence (reduced) of 0.1 mol/L dithiothreitol. The gel was stained with Coomassie brilliant blue. Molecular mass markers (M) are 30, 46, 66, 97, and 220 kd from bottom to top, respectively. (B) Effect of the conA fractions on rosette formation. The rosetting assay was conducted as described in the legend to Figure 1, and the fractions were used at 10% (vol/vol) each, for all experiments. Two different batches of serum were fractionated, and the assay was conducted in duplicate for each batch (mean ± SD for 4 experiments).