<p>There is described an apparatus for measuring protein characteristics comprising an X-ray fluorescence (XRF) spectrometer comprising a source of polychromatic X-rays, an X-ray detector, a protein, a molecule that has been exposed to and at least weakly binds to the protein, a plurality of X-ray fluorescence signal data obtained by irradiating chemical elements in the protein and molecule with the polychromatic X-rays and a security system for maintaining records for the data from the plurality of X-ray fluorescence signal measurements. There is also described an x-ray microscope for measuring a sample.</p>