Liquid sample delivery techniques for serial femtosecond crystallography.

Area of Science:

• Structural biology
• Biophysics
• X-ray science

Background:

• X-ray free-electron lasers (XFELs) enable protein structure determination from micro- and nanocrystals at room temperature by overcoming radiation damage.
• Serial femtosecond crystallography (SFX) experiments require rapid sample delivery to match high X-ray repetition rates (120 Hz to 1 MHz).
• Efficient liquid injection systems are crucial for delivering microcrystals in solution into the X-ray beam in vacuum for SFX.

Purpose of the Study:

• To compare various liquid injection techniques for microcrystals in solution for X-ray free-electron laser experiments.
• To identify methods for optimizing sample delivery and minimizing waste in SFX.
• To address the challenge of matching liquid flow rates to X-ray repetition rates.

Main Methods:

• Comparison of different liquid injection techniques for microcrystal delivery.
• Evaluation of sample delivery efficiency under vacuum conditions.
• Analysis of techniques to mitigate sample waste.

Main Results:

• Different liquid injection methods exhibit varying efficiencies in delivering microcrystals to the X-ray beam.
• Techniques exist to manage sample waste caused by flow rate mismatches with X-ray repetition rates.
• Optimized injection is key for successful serial femtosecond crystallography.

Conclusions:

• Liquid injectors are essential components for serial femtosecond crystallography at X-ray free-electron lasers.
• The choice of injection technique impacts experimental efficiency and data quality.
• Addressing sample waste is critical for maximizing throughput in XFEL experiments.