Isospin in Reactions

We present several possibilities offered by the reaction dynamics of dissipative heavy ion collisions to study in detail the symmetry term of the nuclear equation of state EOS. In particular we discuss isospin effects on reaction mechanisms, fragment production (Isospin Distillation) and collective flows. We stress the importance of a microscopic relativistic structure of the effective interaction in the isovector channel. The possibility of an early transition to deconfined matter in high isospin density regions is also suggested. We finally select Eleven observables, in different beam energy regions, that appear rather sensitive to the isovector part of the nuclear EOS, in particular in more exclusive experiments.