Important biophysical parameters such as pH and temperature can be analyzed by measuring their effectiveness on protein solubility. Purity of lysozyme can be assessed by many means including ion-spray spectroscopy. One must find a way to quantify the influence of microgravity on crystal quality. In both cases, the use of synchrotron radiation appears to be crucial but results are quite dependent on experimental set-up. Mosaic spread, describing crystal perfection, is experimentally measured by rocking curves , .
Resolution gives the crystal diffraction limit.
In order to perform appropriate comparison between space and ground grown crystals, one may either compare the space grown crystals to the ever best ground crystal or use rigorously the same experimental conditions such as protein concentration, pH, temperature, volume or transportation conditions, time of storage, etc. In the present work, we have used both approaches. The protein is not glycosylated and there is no free cysteine. There are three disulfide bridges. Its physical-chemistry properties and three dimensional structure have been thoroughly described.