Page 68 - Macromolecular Crystallography

AU TOMATION OF CRYS TALLIZATION TECHNIQUES 57

in gel media is in microbatch (Protocols 3.9 and Chayen, N. E. (1997a). The role of oil in macromolecular
3.10). The process is automated and is as simple crystallization. Structure 5, 1269–1274.
as setting the trials in standard microbatch. Tetram- Chayen, N. E. (1997b). A novel technique to control the
ethyl orthosilane (TMOS) has been found to be the rate of vapour diffusion, giving larger protein crystals.
most suitable gel for such microbatch experiments J. Appl. Cryst. 30, 198–202.
Chayen, N. E. (1998). Comparative studies of protein
(Moreno et al., 2002).
crystallization by vapour-diffusion and microbatch tech-
niques. Acta Crystallogr. D 54, 8–15.
Chayen, N. E. (2003). Crystallisation of membrane pro-
3.8 Concluding remarks teins in oils. In: Methods and Results in Crystallization of
Membrane Proteins, Iwata, S., ed. International University
Obtaining high-quality crystals is becoming increas-
Line, USA, pp. 131–139.
ingly crucial to progress in the postgenomic era.
Chayen, N. E. (2004). Turning protein crystallisation from
Whether in the individual laboratory, or as part of
an art into a science. Curr. Opinion Structural Biol. 14,
structural genomics projects, it is always vital to
577–583.
have a portfolio of crystallization techniques that can Chayen, N. E. (2005). Methods for separating nucleation
be applied, especially in the cases of proteins that are and growth in protein crystallisation. Prog. Biophys.
proving difficult to crystallize. In order to be useful Molec. Biol. 88, 329–337.
to structural genomics projects, it is also important Chayen, N. E. (2006). Optimization techniques for automa-
to miniaturize and automate as many techniques as tion and high throughput. In Methods in Molecular
possible. Biology, Macromolecular Crystallography Protocols, Vol. 1,
Doublie, S., ed. Humana Press, New Jersey, pp. 175–190.
This chapter has described several alternative
Chayen, N. E. and Helliwell, J. R. (1999). Space-grown
methods to those that are most commonly used. The
crystals may prove their worth. Nature, 398, 20.
useofphasediagramsforoptimizationofthecrystal-
Chayen, N. E. and Saridakis, E. (2002). Protein crystalliza-
lization conditions, control of crystallization kinet-
tion for genomics: towards high-throughput optimiza-
ics, dynamic separation of nucleation and growth, tion techniques. Acta Crystallogr. D 58, 921–927.
and crystallization in gels can now be performed Chayen, N. E., Stewart, P. D. S. and Blow, D. M. (1992).
automatically while using nanolitre or microlitre Microbatch crystallization under oil – a new tech-
volumes of sample. These methods provide a vari- nique allowing many small-volume crystallization trials.
ety of avenues to be explored, either in parallel to J. Crystal Growth 122, 176–180.
conventional methods or when screening and subse- Chayen, N. E., Stewart, P. D. S., Maeder, D. and Blow,
quent fine tuning of the initial screening conditions D. M. (1990). An automated-system for microbatch pro-
have failed to produce high-quality crystals. tein crystallization and screening. J. Appl. Cryst. 23,
297–302.
Chayen, N.E., Boggon, T.J., Casetta,A., Deacon,A., Gleich-
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