Macromolecular Crystallisation, Weizmann Institute, Israel

About Macromolecular Crystallisation, Weizmann Institute, Israel

Crystallisation screening: Utilizing the sitting and hanging drop by vapor diffusion methods for crystallising soluble proteins, using the Mosquito, and LCP Mosquito crystallisation robots.

Service Availability:

Remote

Instruments Available:

The ISPC employs: rapid dispensing of both ‘sitting’ and ‘hanging’ drops for vapor diffusion utilizing a Mosquito robot. Setting up crystallization trials at 4º and 19ºC. Development and utilization of an optimization technique, using the Mosquito robot, to go rapidly and routinely from initial crystals to crystals suitable for X-ray data collection. Use of visualization/storage robots (Formulatrix) for routine viewing and assessment of hundreds of thousands of crystallization drops.

User Guide

For crystallisation trials we will need a sample which is:

Pure as assessed by SDS-PAGE
Homogeneous i.e. devoid of truncated proteins, isomorphs, or incorrectly folded molecules
A reproducible source of several milligrams of the pure protein
The protein should be at an optimal concentration, in the range of 10-40mg/ml, as determined in a pre-crystallisation trial by the crystallisation unit. The salt concentration should be as low as possible, the buffer concentration should be 20-50mM, at a pH close to neutral, and potassium should be avoided if possible
For each of 96 crystallisation conditions (one plate regardless of the crystallization method used) 25μl of protein is needed. 150μl of protein is needed for initial screening