Protein crystallization in a 100 nl solution with new stirring equipment

Area of Science:

• Biophysics
• Crystallography
• Biochemical Engineering

Background:

• Protein crystallization is crucial for structural biology.
• Controlling solution dynamics, like stirring, can impact crystal formation.
• Previous methods lacked precise control over agitation.

Purpose of the Study:

• To develop and evaluate a novel microfluidic stirring system for protein crystallization.
• To quantitatively assess the effects of controlled stirring on crystal growth.
• To determine optimal stirring parameters for hen egg-white lysozyme crystallization.

Main Methods:

• Developed a microfluidic device generating Hagen-Poiseuille flow for precise agitation of ~100 nl protein solutions.
• Crystallized hen egg-white lysozyme under various stirring conditions.
• Evaluated crystal quality and quantity based on stirring parameters, including the Reynolds (Re) number.

Main Results:

• The new system provides well-defined flow patterns and velocities.
• Intermittent flow and low Reynolds (Re) numbers were identified as key factors for improved crystallization.
• Optimal conditions led to the growth of fewer, larger lysozyme crystals.

Conclusions:

• Controlled microfluidic stirring significantly influences protein crystallization outcomes.
• Intermittent flow and low Reynolds numbers are beneficial for obtaining larger, higher-quality protein crystals.
• This system offers a precise tool for optimizing crystallization protocols in structural biology.