(A) Singlet FACS scatter profile of aldehyde-sulfate latex beads, 0.96 μm in diameter, coated with the different antigens and antigen combinations indicated in the graphs, and stained with Alexa-Fluor 488-conjugated 44.1 (anti-PPS14) mAb and Alexa-Fluor 633 conjugated DC-10IA5 (anti-PspA) mAb. The PspA, PPS14 or PPS14-PspA conjugate content per 109 beads and the amount of PPS14-PspA conjugate equivalents in PPS14+[PspA] beads, as determined by ELISA, is indicated in each of the representative preparations. For beads containing simultaneously PPS14 and PspA, the equivalent weight of PPS14-PspA conjugate is indicated. (B) Kinetics of release of the PPS14 attached to beads with stabilization of the PPS14 attachment (by reduction with cyanoborohydride) or without stabilization. Beads coated with PPS14 were maintained at 4°C in PBS for the time indicated. The amount of PPS14 in the supernatant (Free), and attached to the beads (Beads) once collected by centrifugation, was determined by ELISA and expressed as a percentage of the total amount of PPS14 initially attached to the beads.