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Checklist
Checklist
Dear collaborator
We have composed a “Checklist” in order to collect as much information as possible from your protein sample before we start the planning of crystallization experiments. The information you supply will be used in the planning, and will increase the chance of success. Your protein sample is expensive and precious, and this information will also reduce the risk of wasting sample on trials that in retrospect should have been avoided.
As a standard routine, we will normally run the concentrated sample on a SDS-PAGE prior to crystallization. This is not because we do not trust your evaluation, but we will make sure that storage and/or transport have not reduced the quality. We also, as a standard procedure, evaluate the sample by the use of “Dynamic Light Scattering”. DLS will give indication of possible problems due to aggregation, oligomerisation or other sources of heterogeneity of the samples.
Analysis of the amino acid sequence can also give us information about particular features of the protein that we should take into consideration when we plan the crystallization trials.
Generally, crystallization is best achieved from a protein solution with a concentration as high as possible. Due to this, some knowledge about the solubility is useful. If the protein is stable and can be stored at high concentrations, you can supply us with a concentrated sample. Otherwise, we concentrate the sample just prior to the crystallization trials, based on your advises for procedures (can filters be used, precipitation etc). If we do not know exact values for the solubility, a good rule of thumb is to try to obtain a concentration in the order of 10-20 mg/ml.
The checklist is based on “a general” case and some of the information we ask for is not relevant in all cases. Also, we do not ask you to carry out additional time-consuming tests, but if known, this will be useful information to us.
The checklist must be completed and send to the centre together with your protein.
The checklist can be found here (Word document).
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