  The specific morphology of germinal centers is analyzed in the context of the
optimization of the humoral immune response. The relevance of dark and light
zones for the affinity maturation process is investigated in the framework of a
theoretical model for the germinal center reaction. Especially, it is shown
that an intermediate appearance of dark zones in germinal center reactions is
advantageous for the process of antibody optimization. Methodological aspects
are discussed.
