view article
Figure 1
Lysozyme crystal size control by droplet volume scaling. (a) Protein crystallization droplets generated at kilohertz frequencies by combining streams of lysozyme, mother liquor and fluorinated oil. (b) Using different devices and flow rates (see Table S1 of the supporting information), monodisperse droplets (CV < 4%) can be produced with picolitre to femtolitre volumes. (c) Lysozyme crystals produced under batch conditions (control, blue) were on average 8 µm long. The length of lysozyme crystals produced in droplets (salmon) correlates with the droplet volume, with ∼3 µm-long crystals produced in the smallest 0.89 pl droplets. Crystal uniformity emerges when the average number of crystals per droplet (λ) is ≤0.1. (d) and (e) Visual comparison of lysozyme crystals prepared in batch (control) and extracted from 0.89 pl droplets by breaking the emulsion. (f) Droplet volume miniaturization is associated with reduced crystal density normalized to crystals per nanolitre (green) which correlates with increasing the surface area to volume (SA:V, grey) ratio. The batch crystal density value is denoted by the green dashed line. (g) Gains in droplet generation frequency scale with droplet volume reduction.

IUCrJ
Volume 11| Part 2| March 2024| Pages 237-248
ISSN: 2052-2525
https://doi.org/10.1107/S2052252524001799