Techniques for recording and analysing fibre diffraction data from DNA using the instrument D19 at the Institut Laue-Langevin Reactor Source and the instrument SXD at the Rutherford Appleton Laboratory ISIS Spallation Source are described and compared. Data recorded from a specially prepared sample of deuterated DNA in the A conformation using SXD are compared with previously analysed data from a normally hydrogenated DNA in the same conformation recorded on D19. A preliminary Fourier difference analysis of these two datasets has allowed their consistency to be established.