We use the theory of
-tilting
modules to construct cellular bases for centralizer algebras. Our
methods are quite general and work for any quantum group
attached to a Cartan matrix and include the nonsemisimple cases for
being a
root of unity and ground fields of positive characteristic. Our approach also generalizes
to certain categories containing infinite-dimensional modules. As applications, we give
a new semisimplicity criterion for centralizer algebras, and we recover the cellularity of
several known algebras (with partially new cellular bases) which all fit into our general
setup.