Intrinsic viscosities of polyelectrolytes in the absence and in the presence of extra salt: Consequences of the stepwise conversion of dextran into a polycation

► Intrinsic viscosities [η] reflect coil dimensions in the limit of infinite dilution charging. ► Dextran expands isolated coils in pure water by a factor of 80. ► Adding salt to the solutions leads to their shrinkage by at least one order of magnitude. ► All dependencies can be modeled quantitatively.