Data collection from crystals grown in microfluidic droplets

DOI: 10.1107/S2059798322004661

Authors: Gyorgy Babnigg (Argonne National Laboratory) , Darren A. Sherrell (Argonne National Laboratory) , Youngchang Kim (Argonne National Laboratory) , Jessica L. Johnson (Argonne National Laboratory) , Boguslaw Nocek (Argonne National Laboratory) , Kemin Tan (Argonne National Laboratory) , Danny Axford (Diamond Light Source) , Hui Li (Argonne National Laboratory) , Lance Bigelow (Argonne National Laboratory) , Lukas Welk (Argonne National Laboratory) , Michael Endres (Argonne National Laboratory) , Robin L. Owen (Diamond Light Source) , Andrzej Joachimiak (Argonne National Laboratory; University of Chicago)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Acta Crystallographica Section D Structural Biology , VOL 78

State: Published (Approved)
Published: August 2022

Abstract: Protein crystals grown in microfluidic droplets have been shown to be an effective and robust platform for storage, transport and serial crystallo­graphy data collection with a minimal impact on diffraction quality. Single macromolecular microcrystals grown in nanolitre-sized droplets allow the very efficient use of protein samples and can produce large quantities of high-quality samples for data collection. However, there are challenges not only in growing crystals in microfluidic droplets, but also in delivering the droplets into X-ray beams, including the physical arrangement, beamline and timing constraints and ease of use. Here, the crystallization of two human gut microbial hydrolases in microfluidic droplets is described: a sample-transport and data-collection approach that is inexpensive, is convenient, requires small amounts of protein and is forgiving. It is shown that crystals can be grown in 50–500 pl droplets when the crystallization conditions are compatible with the droplet environment. Local and remote data-collection methods are described and it is shown that crystals grown in microfluidics droplets and housed as an emulsion in an Eppendorf tube can be shipped from the US to the UK using a FedEx envelope, and data can be collected successfully. Details of how crystals were delivered to the X-ray beam by depositing an emulsion of droplets onto a silicon fixed-target serial device are provided. After three months of storage at 4°C, the crystals endured and diffracted well, showing only a slight decrease in diffracting power, demonstrating a suitable way to grow crystals, and to store and collect the droplets with crystals for data collection. This sample-delivery and data-collection strategy allows crystal droplets to be shipped and set aside until beamtime is available.

Journal Keywords: X-ray data collection; fixed targets; serial crystallography; sialate O-acetylesterase; fucosidases; α–β fold; hydrolases; microfluidic droplets; low dose; emulsions

Subject Areas: Biology and Bio-materials, Technique Development


Instruments: I24-Microfocus Macromolecular Crystallography

Other Facilities: 19-ID at APS

Added On: 25/07/2022 10:31

Discipline Tags:

Technique Development - Life Sciences & Biotech Structural biology Life Sciences & Biotech

Technical Tags:

Diffraction Serial Synchrotron Crystallography (SSX)