A microchannel plate delay line X-ray detector system will be developed. These detectors will have high accuracy, high resolution, large area, and large count rate capability. The detectors would be ideal for measurements on protein crystals with very large unit cells, and will be well suited for multiwavelength anomalous dispersion measurements. The detector will consist of a thin X-ray scintillator, a semi- transparent photocathode, a pair of microchannel plates, and orthogonal delay line anodes. Delay line readout of large size microchannel plates will be studied, and different plates will be compared. The detector system, once developed, will enhance efforts in structural biology.