Microcrystal screening with a novel design for beamline-mountable crystallization wells

A simple and flexible system is described for in situ screening of microcrystals of membrane proteins that are grown within a connected-bilayer matrix formed by hydrated lipids. Using sheets of appropriate polymer materials to create a thin multiwell cassette, crystals can be evaluated by UV microscopy as well as by more conventional forms of light microscopy. Crystallization wells can be individually excised and mounted for diffraction screening on a synchrotron X-ray source. In addition, crystallization hit rates were significantly improved by employing a vapor diffusion approach rather than the batch crystallization method that is normally used with hydrated-lipid gels.