Project Summary The New York Structural Biology Center (NYSBC) owns and operates the NYX beamline at the National Synchrotron Light Source II (NSLS-II) which is located at the Brookhaven National Laboratory (BNL) and operated for the benefit of the member institutions of the NYSBC and the community of non-consortium-member structural biologists. We seek funds to acquire a Dectris Eiger2 XE 9M X-ray detector for macromolecular crystallography. This advanced, high-speed readout of the detector will significantly increase the throughput of samples and therefore increase the number of projects that can be prosecuted in a set amount of time. The high frame rate will allow us to perform advanced crystallographic methods that are not possible with our current experimental setup, such as serial crystallography, ultra-fast rastering and potentially outrunning radiation damage during data collection. NYX has been operating with a prototype pixel array detector from Area Detector Systems Corporation (HF-4M) since its inception at NSLS-II. While the data quality from this detector has been comparable with other available detectors, ADSC ceased to operate several years ago with the result that the detector is no longer serviceable and is starting to fail. In order to remain valuable to users, it is imperative that we replace the ADSC HF-4M with a modern pixel array detector with the expectation that it will remain useful and serviceable for the next 8-10 years. Of particular importance is performing this upgrade prior to the temporary shutdown of the Advanced Photon Source for a facility upgrade in 2022 when the demand for synchrotron access for NIH-funded projects is expected to increase dramatically. Having this detector in place in 2021 will allow NYX to significantly enhance the NIH-funded research programs of the NYSBC consortium members, non- consortium members as well as be fully prepared to provide uninterrupted access to NIH-funded projects due to the temporary closure of the APS.