A 3D printed hybrid nozzle device combining a microfluidic mixer with a liquid jet injector that addresses the bottleneck of investigating substrate-initiated biological reaction paths employing serial crystallography with XFELs. The hybrid nozzle provides for injecting aqueous protein crystal jets after fast mixing (<5 ms), reaching reaction time points (e.g., about 10 ms to about 150 ms) suitable to resolve enzyme kinetics.