Dispense 24-well hanging drop experiments with Oryx4 and Oryx8

Douglas Instruments has released new software and hardware for automatic 24-well cover slide dispensing. The new method can dispense up to 5 drops per slide, making it easy to adjust the ratio of protein and reservoir solution in the drops, and to add e.g. seed stock or additive.

You can quickly set up powerful experiments that would take too long to do by hand.

The XStep optimization software also enables users to fill the reservoirs of the source plate. This makes creating PEG vs pH grids and multivariate optimization designs simple. The system can then dispense the drops.

  Technical tip: Scaling up from nano-drops to micro-drops

If you set up your initial screens with 100 nl (protein) + 100 nl (reservoir solution) drops, it's quite likely that you will have to scale up to larger drops in order to get crystals that are large enough to collect data from.

If you take the same solutions and simply increase the volume to say 1 + 1 µl, you will often get precipitation instead of crystallization. This is a counterintuitive result because people correctly believe that the smaller drops will dry out more quickly, and they therefore assume that they will see more precipitation in the smaller drops.

However, the situation becomes clear when you realize that there are two important differences between large and small drops:

1. The surface area to volume ratio is greater for the smaller drops (to put it another way, more of the small drop is close to the surface).

2. The smaller drops equilibrate with the reservoir more quickly.

Read more about Scaling up on our website….

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If you would like further information or have any questions please contact Stefan Kolek:

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

or Stefan@douglas.co.uk

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

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