Combination of oils and gels for enhancing the growth of protein crystals

This note focuses on two different ways of enhancing the use of gels in protein crystallization by applying oils to the trials. Using a five-channel motorized syringe setup, crystals were grown in gelled microbatch drops under oil and compared with those grown under similar conditions in standard microbatch drops. The advantage of this technique over existing gel techniques is that numerous trials can be dispensed automatically, while consuming very small quantities of protein. The application of oil to improve the gel acupuncture technique was also investigated; crystal growth in the presence of an oil barrier was slower than in its absence, giving rise in each case to a single large crystal with no precipitation nor smaller crystals in the capillary.