New plate for optimization now available from Douglas Instruments

The MRC Maxi optimization plate is a new design for macromolecular crystallization presented in a 48 well format. The Oryx range of crystallization robots can easily set up 48 large (4+4 µL) sitting drops into this plate. Just type the volumes that you would like into the experiment designer.

Manufactured by SwissCI AG, the plate offers an SBS footprint while providing 48 wells. The MRC Maxi is intended for large drops and is compatible both with standard robotic systems as well as manual pipetting.

Using Oryx robots and our screening software WaspRun crystallizers can set up many types of experiment with the MRC Maxi plate including Microseeding, Additive Optimization, Scaling Up, 4 Ingredient Gradients and Cross Matrix Designs.

Oryx 8 also has the benefit of X-Step optimization software. Users can dispense screen solutions to the reservoir wells. X-Step allows users to quickly design gradient type optimizations or up to 7 dimensional multivariate experiments.

  Technical tip: Conversion of Vapor Diffusion experiments
to Microbatch-Under-Oil

A challenge for crystallographers wishing to use the microbatch-under-oil approach is how to translate a known crystallization condition from microbatch to vapor diffusion, or vice versa.

Douglas Instruments recommends the following 3 steps for converting vapour diffusion drops to microbatch under oil:

1. Precipitant concentration is normally lower in the microbatch drop than in the vapor diffusion reservoir. Set up microbatch trials covering a range of concentrations from just below the concentration used in the reservoir, to half of this concentration.

2. Protein concentration is normally slightly lower than the stock solution used in vapor diffusion (i.e. the protein concentration before mixing it with well solution). Test a range from the concentration of the vapor diffusion protein stock solution to half this concentration.

3. In cases where crystallization takes place very rapidly, or where equilibration is slow (e.g. using high concentrations of polymers such as PEG), crystallization may take place in vapor diffusion before the diffusion equilibrium is complete. In such cases, the microbatch concentrations of protein and precipitant may be close to the concentrations in the vapor diffusion drop immediately after setting up (before equilibration takes place).

for more on this see our website

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If you would like further information or have any questions about the topics in this newsletter, please contact me:

Tel: + (44) 1488 649090 US toll free: 1-877-225-2034

or Stefan@douglas.co.uk

With best regards,
Stefan Kolek

To request a service please contact Stefan@douglas.co.uk.
To request a demonstration please contact Hilary@douglas.co.uk

Douglas Instruments