  We study unzipping of a complementary RNA-DNA helix applied to an external
force, focusing on the force-force correlations. While at the microscopic level
these are given by the sequence, the experiment measures effective, macroscopic
correlations. The latter are sequence-independent, i.e. universal, and
constitute the central object of the underlying field theory of disordered
systems. Comparing field-theory predictions and the exact solution of a 1-d toy
model with the experiment, we find an excellent agreement, confirming
fundamental theoretical concepts via a biologically inspired experiments.
