  Critical exponents are computed for a variety of twist-2 composite operators,
which occur in polarized and unpolarized deep inelastic scattering, at leading
order in the 1/N_f expansion. The resulting d-dimensional expressions, which
depend on the moment of the operator, are in agreement with recent explicit two
and three loop perturbative calculations. An interesting aspect of the critical
point approach which is used, is that the anomalous dimensions of the flavour
singlet eigenoperators, which diagonalize the perturbative mixing matrix, are
computed directly. We also elucidate the treatment of gamma^5 at the fixed
point which is important in simplifying the calculation for polarized
operators. Finally, the anomalous dimension of the singlet axial current is
determined at O(1/N_f) by considering the renormalization of the anomaly in
operator form.
