Automated gradient equilibration of macromolecular crystals to new solution conditions

Area of Science:

• Crystallography
• Biochemistry
• Structural Biology

Background:

• Macromolecular crystals are vital for determining biological structure.
• Current methods for changing crystal solutions can cause damage and are labor-intensive.

Purpose of the Study:

• To present a novel, automated device for ambient solution exchange in macromolecular crystallography.
• To demonstrate a gentle and cost-effective method for crystal equilibration.
• To improve the workflow for crystal structure determination and solution composition studies.

Main Methods:

• Development of an open-source device for controlled solution exchange.
• Implementation of a gradient equilibration technique.
• Testing with three different macromolecular crystals, with exchange times from 5 to 180 minutes.

Main Results:

• The device successfully prevented crystal cracking during solution exchange, unlike direct transfer methods.
• Equilibration times ranged from 5 to 180 minutes, demonstrating versatility.
• Crystals processed with the device yielded high-quality diffraction data.
• Refined structures were comparable to those obtained through previous methods.

Conclusions:

• The described device offers a systematic, labor-saving, and gentle approach to macromolecular crystal solution exchange.
• This method enhances crystal quality and structural analysis efficiency.
• The open-source nature facilitates broader adoption in structural biology research.