Segmented milli-fluidic crystallisation of paracetamol with in situ single-crystal X-ray diffraction

Area of Science:

• Crystallography
• Materials Science
• Chemical Engineering

Background:

• Serial crystallography mitigates radiation damage in protein crystal analysis by combining data from multiple crystals.
• Increasing X-ray beam brightness poses radiation damage challenges for small molecule crystals.
• Flow crystallization offers potential for high-throughput screening and kinetic studies.

Purpose of the Study:

• To demonstrate the feasibility of serial crystallography for small molecule crystals in a flow crystallization environment.
• To present the first known example of in situ single crystal X-ray diffraction of small molecule crystals using flow crystallization.
• To explore applications in high-throughput screening and kinetic studies for mm-scale small molecule crystals.

Main Methods:

• Combining serial crystallography with segmented flow cooling crystallization.
• Utilizing in situ single crystal X-ray diffraction on growing crystals within flowing tubing.
• Implementing a flow system where crystals rotate freely within the X-ray beam for 4.2 seconds.
• Employing fluid dynamics to maintain crystal rotation and position within the beam.

Main Results:

• Achieved structure solution of paracetamol form I at 0.8 Å resolution using data from 13 crystals.
• Demonstrated the ability to extract unit cell information from a single crystal.
• Successfully performed single crystal X-ray diffraction on small molecule crystals in a flow crystallization setup.

Conclusions:

• Serial crystallography coupled with flow crystallization is a viable technique for small molecule crystal analysis.
• This integrated approach facilitates high-throughput screening and kinetic studies of small molecule crystals.
• The method shows promise for analyzing crystals up to mm-scale, overcoming radiation damage limitations.