Figure 1: Schematic view of the experimental lay-out for in situ μ-GISAXS simulation of protein crystallization by Langmuir-Blodgett (LB) nanotemplate method. The experimental set-up has been mounted at ID13 beam-line at ESRF, as described more in details in Gebhardt et al. [34-36]. The vapor deposition cylinder contains two stainless Kapton windows (transparent to the X-rays) and the Lysozyme/Thaumatin solution typical droplet hanging on the Lysozyme/Thaumatin two layers deposited over the glass. The cylinder is mounted on an xyz gantry and a two-axis goniometer (φx, φy). The scan is made in the y direction. αi denotes the angle between the incident beam and the sample surface, αf the corresponding exit angle, and 2φ the out-of-plane angle. The flight path (L = 1.15 m) between the sample and the two-dimensional detector is evacuated (10-2 mbar). On the right is shown the typical two-dimensional μGISAXS signal of the Lysozyme/Thaumatin drop sitting on a layer. Above, the working hypothesis (the model of the pathway association within the LB nanobiotemplate, leading to the crystal nucleation and growth) is shown.