The table shows five different conditions of the bead-assay. The beads were incubated alternatively with anti-goat antibody, goat-anti-human antibody, SP-A (1 ng recombinant human standard, final concentration 100 ng/ml) or SP-D (1 ng recombinant human standard, final concentration 100 ng/ml) in a buffer containing calcium ions. The "+" means that the reagent was used. After incubation the mixture was analyzed by light microscopy and agglutination was only detected under condition 1 when SP-A was added. The experiments were repeated three times.