Figure 2.

Effect of the dilution of the reaction system on antibody uptake. Y-axes are the same as in figure 1. Antibodies are also the same, but they are supposed to have an initial concentration corresponding to a ‘++’ in the antiglobulin test. If a suitable medium is added, which dilutes the system without changing temperature, pH, or ionic strength, anti-D and anti-c are markedly affected and the antibody uptake may be insufficient to be detected. A high affinity antibody, such as anti-K, is much less affected.