Farfield Group Ltd. has pioneered the use of a method known as Dual Polarisation Interferometry (DPI) for detecting macromolecular crystal nucleation at its very start.

The technology is based on a waveguide structure which supports light confined within a core. Information is obtained by studying the change in the propagation velocity of light travelling through the waveguide structure, which manifests itself as a change in the position of interference fringes. When crystals begin to form, light loss from the top of the waveguide increases dramatically, rapidly leading to the loss of the interference fringes. The (contrast) loss observed appears to be unique to the process of crystallisation.